The GAMCO Global Growth FundShareholder Commentary – September 30, 2016

To Our Shareholders,

Thank you for your investment in The GAMCO Global Growth Fund.

For the quarter ended September 30, 2016, the net asset value (“NAV”) per Class AAA Share of The

GAMCO Global Growth Fund increased 4.6% compared with an increase of 5.3% for the Morgan Stanley

Capital International (“MSCI”) All Country (“AC”) World Index. See page 2 for additional performance

information.

Record low interest rates, a bounce in consumer spending and a surge in July payroll growth combined

to elevate stocks (the S&P) to a record high in mid-August. Additionally, after falling in the first half of the

quarter, oil prices surged, which some viewed as constructive for economic growth. (Certainly some of the

price rise can be attributed to oil patch rumors of a deal to reduce oil output, involving Saudi Arabia, Russia

and Iran, among others.) The Federal Reserve Board continues to refrain from tightening monetary policy as

overall economic data remains mixed. The Fed has not tightened since last December, after forecasting four

quarter point tightening moves for 2016 when the year began.

Overseas there is continued fallout regarding June’s Brexit vote in the United Kingdom, primarily being

transmitted via depreciation in the pound sterling. Fears over the health of Deutsche Bank continue to surface

as its share price hit an all-time low in late September. Other Eurozone banks, especially in Italy, remain a

source of concern. Europe continues to rely on monetary policy to stimulate growth and negative interest rates

are increasingly widespread. Such rates are controversial and may not achieve their desired objectives of

stimulating spending and inflation.

Caesar M. P. Bryan Howard F. Ward, CFA

(Y)our Portfolio Management Team

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Average Annual Returns through September 30, 2016 (a)

Since Inception Quarter 1 Year 3 Year 5 Year 10 Year (2/7/94) ———— ——— ——— ———— ———— —————

Class I (GGGIX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.77% 9.64% 5.08% 13.66% 6.37% 8.58%

Class AAA (GICPX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.57 8.82 4.49 13.15 6.02 8.42

MSCI AC World Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.30 11.96 5.17 10.63 4.34 6.24(d)

Lipper Global Large-Cap Growth Fund Classification . . . . . 5.36 10.41 5.55 11.32 5.21 7.02

Class A (GGGAX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.57 8.84 4.50 13.17 6.02 8.43

With sales charge (b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (1.45) 2.58 2.46 11.83 5.40 8.15

Class C (GGGCX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.38 8.02 3.71 12.31 5.23 7.83

With contingent deferred sales charge (c) . . . . . . . . . . . . . . 3.38 7.02 3.71 12.31 5.23 7.83

In the current prospectuses dated April 29, 2016, the gross expense ratios for Class AAA, A, C, and I Shares are1.68%, 1.68%, 2.43%, and 1.43%, respectively, and the net expense ratios for these share classes aftercontractual reimbursements by Gabelli Funds, LLC, (the "Adviser") are 1.68%, 1.68%, 2.43%, and 1.00%,respectively. Class AAA and Class I Shares do not have a sales charge. The maximum sales charge for ClassA Shares and Class C Shares is 5.75% and 1.00%, respectively.

(a) Returns represent past performance and do not guarantee future results. Total returns and average annual returnsreflect changes in share price, reinvestment of distributions, and are net of expenses. Investment returns and theprincipal value of an investment will fluctuate. When shares are redeemed, they may be worth more or less thantheir original cost. Current performance may be lower or higher than the performance data presented. Visitwww.gabelli.com for performance information as of the most recent month end. Returns for Class I Shares wouldhave been lower had the Adviser not reimbursed certain expenses. The Fund imposes a 2% redemption fee onshares sold or exchanged within seven days after the date of purchase. Performance returns for periods of less thanone year are not annualized. Investors should carefully consider the investment objectives, risks, charges, andexpenses of the Fund before investing. The prospectuses contain information about these and other matters andshould be read carefully before investing. To obtain a prospectus, please visit our website at www.gabelli.com.Investing in foreign securities involves risks not ordinarily associated with investments in domestic issues, includingcurrency fluctuation, economic, and political risks. The Class AAA Share NAVs are used to calculate performancefor the periods prior to the issuance of Class A Shares, Class C Shares, and Class I Shares on March 2, 2000, March12, 2000, and January 11, 2008, respectively. The actual performance of the Class A and Class C Shares wouldhave been lower due to the additional fees and expenses associated with these classes of shares. The actualperformance of Class I Shares would have been higher due to lower expenses related to this class of shares. TheMSCI AC World Index is an unmanaged market capitalization weighted index that is designed to measure the equitymarket performance of developed and emerging markets. The MSCI AC World Index consists of 45 country indicescomprising 24 developed and 21 emerging market country indices. The Lipper Global Large-Cap Growth FundClassification reflects the performance of mutual funds classified in this particular category. Dividends areconsidered reinvested. You cannot invest directly in an index.

(b) Performance results include the effect of the maximum 5.75% sales charge at the beginning of the period.(c) Assuming payment of the 1% maximum contingent deferred sales charge imposed on redemptions made within one

year of purchase.(d) MSCI AC World Free Index since inception performance is a blend of Gross Performance excluding applicable

taxes and Net Performance. This benchmark's Net Performance began on December 29, 2000.

We have separated the portfolio managers’ commentary from the financial statements and investment portfolio

due to corporate governance regulations stipulated by the Sarbanes-Oxley Act of 2002. We have done this to

ensure that the content of the portfolio managers’ commentary is unrestricted. Both the commentary and the

financial statements, including the portfolio of investments, will be available on our website at

www.gabelli.com.

Although economic data in China improved during the quarter, this was largely attributable to government

stimulus measures—the sustainability of the better data is suspect. Japan’s economy continues to go nowhere

fast, despite the extraordinary measures of Abenomics designed to jumpstart growth. Japan needs real

structural reform to address a declining population and that has not happened. Negative interest rates in Japan

resulted in a stronger yen—the opposite of what was desired.

On balance, we are growing more cautious on the global economic outlook. We don’t think the U.S.

election is a game changing event as we believe the most likely outcome is a continuation of divided

government with incremental change.

The Economy

The U.S. economy continues to grow at a modest pace. While the third quarter may register 2.5% growth,

fourth quarter growth is likely to be slower. While inventory restocking will provide a bit of a boost to third

quarter growth, payroll growth appears to be slowing, corporate profits are being squeezed by rising labor costs

and consumers are largely reluctant to boost spending by borrowing. At the same time, credit conditions are

becoming more restrained and interest rates have ticked higher, as has the unemployment rate. Furthermore,

oil prices have risen and may rise further if much rumored production cuts are agreed upon by the major oil

exporting countries. Growing calls for trade protectionism present another red flag.

While we don’t see a recession next year at this time, the risk of such an outcome has risen. Global trade,

an important variable in global growth, is slowing. Global growth expectations for 2017 have been cut. We

suspect profit expectations for 2017 are too high. Profit margins peaked about two years ago. If the profit

outlook deteriorates further - which seems probable given rising wage pressure and little revenue growth - we

could see down earnings, which would ring the recession alarm bells. Lower profits would put employment

gains, consumer spending and capital expenditure levels at risk. With consumers showing little appetite to take

on new debt, the Fed’s ability to stimulate the economy with lower interest rates is limited.

The slowdown in global trade is worrisome. Exports are an important source of marginal growth for many

countries, including China and Japan amongst the largest economies. Global debt loads are at a record high.

China, as well as Japan, likely has unsustainably high debt loads, which combined with aging demographics

spell trouble, especially if its exports are in decline. We will be watching the monthly global PMI reports

closely—readings below 50 increase the risk of some type of financial accident. We should be worried about

global financial market stability if the dollar strengthens too much. Although other outcomes are possible, a

gratuitous Fed tightening might trigger both dollar strength and a significant negative reaction from stocks. We

believe, perhaps naively, that the Fed's leadership understands this and consequently we don’t expect the Fed

to tighten this year. On the other hand, it is probably fair criticism to say that the Fed is overly influenced and

concerned about market sentiment and short-term market volatility.

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The Markets

Yes, this time something is very different. How else to explain global interest rates hitting all-time lows this

past quarter? Negative interest rates, prominent in Europe and Japan now, are historic. Negative rates imply

that the time value of money is negative! My economics textbooks from the 1970s don’t even mention the

possibility of negative rates. The Brexit vote in late June was the catalyst for the latest dip in rates, which

bottomed in July in most cases. The Bank of England announced additional easing measures as investors

panicked over the prospects of an imminent recession in the UK. Cooler heads have since prevailed and

recession is no longer the base case forecast for the UK next year.

Investors are increasingly questioning the wisdom of negative rates and the efficacy of monetary policy in

a world where consumers are reluctant to borrow when rates are already so low. Many baby boomers need to

build savings for retirement so they can’t take on more debt. In short, monetary policy is hitting the laws of

diminishing returns and business confidence is now in decline. This means central bankers are losing the

degree to which they can control economic growth. Furthermore, the existing high government debt load inhibits

using fiscal policy to fire up economic growth. If investment is curtailed by a lack of profit growth, the extra heavy

lifting will be put on the back of exports. Hence, there is ongoing pressure to lower currency values. At a time

when global trade is already slowing, exports have never been more important and protectionist sentiment is at

its highest level in decades.

All of this means interest rates are staying lower for a longer period of time than we expected even three

months ago. The shortage of yield, on a global basis in major markets, will continue to drive investors into longer

dated Treasury notes and bonds. Stocks too will benefit, unless earnings expectations are reset lower, which is

possible. Can price to earnings multiples rise to offset lower profits, if necessary? That is a hard case to make

if earnings are actually falling. Stocks are riskier than bonds but do offer potentially better total returns for

investors who can tolerate the volatility and commit to a longer term investment horizon. Stocks are priced at

17 times next year’s expected operating earnings and the market’s dividend yield is 2.1%. The 10 year U.S.

Treasury is yielding 1.7% and sells at 59 times its coupon, which isn’t growing. To reach for the higher current

income, growth in income, and potential growth in capital offered by stocks, you have to accept greater risk of

principal. There is no free lunch.

Portfolio Observations

During the third quarter we became more defensive in our positioning by reducing the portfolio’s exposure

to companies with a relatively high level of economic sensitivity. In short, we reduced the portfolio’s beta but

remained close to fully invested as we are not market timers.

We added five new holdings to the portfolio in the third quarter: O’Reilly Automotive (0.4% of net assets

as of September 30, 2016), Fiserv (0.7%), Sprouts Farmers Market (0.1%), Ulta Salon Cosmetics &

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Fragrance (0.6%), and Zoetis (1.0%). O’Reilly sells auto parts to professional service providers and do-it

yourself (“DIY”) customers. The company also performs repairs for others. It is a domestic business that is

relatively recession resistant and has an outstanding record of growing revenues and earnings over many

years. Fiserv is a financial services technology company whose software facilitates electronic payments and

processing. Sprouts Farmers Market is one of the fastest growing grocers in the U.S. It emphasizes natural

and organic foods at affordable prices. Ulta Salon is the largest beauty retailer in the U.S. with industry leading

comparable store sales of +14.4% last quarter. Lastly, Zoetis is a global leader in animal health medicines for

both livestock and companion animals. Zoetis’ companion animal business is benefitting from the

“humanization of pets” which is resulting in stronger demand for pet healthcare.

We added to a number of existing positions, especially ITV (1.4%), Liberty Global (2.1%), Tencent (2.1%),

Smith & Nephew (1.2%) and Diageo (1.0%)

We eliminated a number of positions as we became more defensively positioned. Sold outright were

Allergan, Baidu, BlackRock, Gilead Sciences, Lennar, LiLAC, Novo-Nordisk, NXP Semiconductors, Qualcomm,

Tesla Motors, Union Pacific, Whirlpool, WhiteWave Foods (takeover offer from Danone) and Zillow Group.

We also reduced various holdings with the largest reductions in Charles Schwab (0.4%), BP (1.0%),

CBS (0.7%), Siemens (1.0%) and Honeywell (1.0%).

Relative to the MSCI All Country World Index, we ended the quarter overweight technology, consumer

discretionary and consumer staples. We were underweight financials, telecommunication services, utilities,

real estate and energy. We were near market weight in health care, industrials and materials. With our more

defensive posture, we are significantly underweight the emerging markets. We believe the slowdown in global

trade will worsen as the U.S. economy slows and negatively impact the emerging markets (including China),

and also Japan, which we are underweight.

Performance Commentary

Holdings that made the most positive contribution to performance for the quarter (based upon price change

and the size of the holding), were, in order, Amazon.com (3.0% of net assets as of September 30, 2016),

Facebook (3.7%) , Alphabet (Google) (3.4%), Microsoft (3.0%), Apple (1.9%), EOG Resources (2.2%), Adobe

Systems (2.3%), Tencent, Siemens and Charles Schwab.

Hurting us the most for the quarter were Bristol-Myers Squibb (1.0%), Novo-Nordisk (sold during quarter),

CVS Health (1.2%), Reckitt Benckiser (1.5%), Lululemon Athletica (0.5%), Sherwin-Williams (1.4%),

Walgreens Boots Alliance (1.5%), Salesforce.com (0.5%), General Electric (0.9%) and Roche (0.4%).

5

In Conclusion

You may have discerned by now that we are more concerned about the economic outlook and more

cautious on the stock market’s prospects than usual. We have positioned the portfolio more defensively and

will likely continue to moderate the Fund’s beta in the weeks ahead. We are positioned for a rising U.S. dollar

environment and weakness in the emerging markets. We are not making an asset allocation change as we do

not believe in market timing and we believe investors in our Fund have made a decision to invest in stocks.

The flow of good economic data may peak between now and the end of 2016, if it hasn’t already. There are

already cracks in the data and next year could be challenging for businesses and investors alike. Stocks could

drift higher on some earnings growth and stable to higher P/E ratios, supported by historically low interest rates.

But the risk of earnings disappointments and potentially lower stock prices has risen. Let’s hope the outlook

improves in the months ahead.

Global Allocation

The accompanying chart presents the Fund’s

holdings by geographic region as of September 30, 2016.

The geographic allocation will change based on current

global market conditions. Countries and/or regions

represented in the chart and discussed in this

commentary may or may not be included in the Fund’s

future portfolio.

Let’s Talk Stocks

The following are stock specifics on selected holdings of our Fund. Favorable earnings prospects do not

necessarily translate into higher stock prices, but they do express a positive trend that we believe will develop

over time. Individual securities mentioned are not necessarily representative of the entire portfolio. For the

following holdings, the share prices are listed first in United States dollars (USD) and second in the local

currency, where applicable, and are presented as of September 30, 2016.

Facebook’s (3.7% of net assets as of September 30, 2016) (FB – $128.27 – NASDAQ) mission is to give

people the power to share and make the world more open and connected. People use Facebook to stay

connected with friends and family, to discover what's going on in the world, and to share and express what

matters to them. As of June 30, 2016, Facebook had 1.71 billion monthly active users (MAUs) worldwide,

including 1.57 billion mobile MAUs. Facebook’s unique cache of user profiles creates a powerful targeted

advetising platform.

Alphabet (3.4%) (GOOG – $777.29 – NASDAQ) is the parent company of Google, which is widely recognized

as the world’s leading Internet search engine. Google’s stated mission is to organize the world’s information

6

United States 60.2%

Europe 28.4%

Asia/Pacific Rim 5.3%Japan 6.1%

HOLdInGS BY GEOGRAPHIC REGIOn

7

and make it universally accessible and useful. Google generates revenue by providing advertisers with the

opportunity to deliver measurable, cost effective online advertising that is relevant to the information displayed

on any given webpage. This makes the advertising useful to consumers as well as to the advertiser placing it.

We believe this highly innovative and fast growing company is uniquely positioned to create new market

opportunities while maintaining its lead in online search.

Amazon.com (3.0%) (AMZN – $837.31 – NASDAQ) opened on the World Wide Web in July 1995. CEO

Jeff Bezos guides the Company on four principles: customer obsession rather than competitor focus, passion

for invention, commitment to operational excellence, and the patience to think long-term. Prime, Fulfillment by

Amazon, 1-Click shopping, Dash Buttons, Kindle Direct Publishing, Kindle, Fire phone, Fire tablets, Fire TV

and Amazon Echo are some of the products and services pioneered by Amazon. Amazon Web Services

(AWS), launched just ten years ago, is the leading public cloud vendor.

Microsoft (3.0%) (MSFT – $57.60 – NASDAQ), the world’s largest software company, develops,

manufacturers, and licenses a range of software products for a variety of computing devices from PCs to

servers to its Xbox game console. While the company’s core desktop operating system and applications

software franchise (Windows/MS Office) is maturing, Microsoft is gaining share in the enterprise market and,

with its Internet and Xbox efforts, in the consumer markets also. The company’s latest operating system,

Windows 10, was released in July, 2015. Microsoft’s Azure is a fast growing public cloud service that competes

with Amazon’s AWS.

KEYENCE (2.6%) (6861.T – ¥74,298 – Tokyo Stock Exchange) has steadily grown since 1974 to become an

innovative leader in the development and manufacturing of industrial automation and inspection equipment

worldwide. Products consist of code readers, laser markers, machine vision systems, measuring systems,

microscopes, sensors, and static eliminators. Today, KEYENCE serves over 200,000 customers in 70 countries

around the world.

Adobe Systems (2.3%) (ADBE – $108.54 – NASDAQ) is the global leader in digital marketing and digital media

solutions. Their tools and services allow customers to create groundbreaking digital content, deploy it across

media and devices, measure and optimize it over time and achieve greater business success. Adobe’s

software and services help customers make, manage, measure and monetize their content across every

channel and screen.

EOG Resources (2.2%) (EOG – $96.71 – NYSE) is one of the largest independent (non-integrated) crude oil

and natural gas companies in the United States with proved reserves in the United States, Trinidad, the United

Kingdom and China. As of December 31, 2015, EOG’s total estimated net proved reserves were 2,118 million

barrels of oil equivalent (MMBoe) and were comprised of 52 percent crude oil and condensate, 18 percent

natural gas liquids (NGLs) and 30 percent natural gas. Approximately 97 percent of these reserves were

located in the United States. EOG’s total worldwide production in 2015 was 209 MMBoe. At year-end 2015,

EOG had approximately 2,750 employees.

8

Liberty Global plc (2.1%) (LBTYA – $34.18 – NASDAQ) is an international provider of video, broadband

internet, fixed-line telephony and movile services. The company’s consumer brands include Virgin Media,

Ziggo, Unitymedia, Telenet, UPC Cablecom, UPC, CTR and Liberty. Liberty Global operates the largest cable

network in Austria, Belgium, Chile, the Czech Republic, Hungary, Ireland, the Netherlands, Poland, Puerto

Rico, Slovakia, Switzerland and the U.K., and the second largest in Germany and Romania.

Schlumberger (2.1%) (SLB – $78.64 – NYSE) is the world’s leading supplier of technology, integrated project

management and information solutions to customers working in the oil and gas industry worldwide. Employing

more than 113,000 people representing over 140 nationalities and working in more than 85 countries,

Schlumberger provides the industry’s widest range of products and services from exploration through production.

Tencent Holdings (2.1%) (700HK – HK$215.64 – Hong Kong Stock Exchange), headquarted in Shenzen, is one

of the largest internet companies in the world and the biggest computer game publisher in the world. The

company infiltrates every aspect of digital life for the Chinese consumer. Its offerings include social network

platforms, instant messaging services, e-commerce marketplaces, online video games, mobile payment

applications and online advertising. As of December 31, 2015, Tencent’s QQ web portal had 853 million monthly

active users (MAUs); the Weixin and WeChat apps, combined, had 697 million MAUs; Qzone, its social media

network, had 573 MAUs.

October 12, 2016

note: The views expressed in this Shareholder Commentary reflect those of the Portfolio Managers only through

the end of the period stated in this Shareholder Commentary. The Portfolio Managers’ views are subject to

change at any time based on market and other conditions. The information in this Portfolio Managers’

Shareholder Commentary represents the opinions of the individual Portfolio Managers and is not intended to be

a forecast of future events, a guarantee of future results, or investment advice. Views expressed are those of

the Portfolio Managers and may differ from those of other portfolio managers or of the Firm as a whole. This

Shareholder Commentary does not constitute an offer of any transaction in any securities. Any recommendation

contained herein may not be suitable for all investors. Information contained in this Shareholder Commentary

has been obtained from sources we believe to be reliable, but cannot be guaranteed.

Top Ten Holdings (Percent of net Assets)

September 30, 2016

Facebook Inc. 3.7%

Alphabet Inc. 3.4%

Amazon.com Inc. 3.0%

Microsoft Corp. 3.0%

Keyence Corp. 2.7%

Adobe Systems Inc. 2.3%

EOG Resources Inc. 2.2%

Liberty Global plc 2.1%

Schlumberger Ltd. 2.1%

Tencent Holdings Ltd. 2.1%

9

Minimum Initial Investment – $1,000

The Fund’s minimum initial investment for regular accounts is $1,000. There are no subsequent

investment minimums. No initial minimum is required for those establishing an Automatic Investment Plan. The

Fund imposes a 2% redemption fee on shares sold or exchanged within seven days after the date of purchase.

See the prospectuses for more details.

www.gabelli.com

Please visit us on the Internet. Our homepage at www.gabelli.com contains information about GAMCO

Investors, Inc., the Gabelli/GAMCO Mutual Funds, IRAs, 401(k)s, current and historical quarterly reports,

closing prices, and other current news.

The Fund’s daily NAVs are available in the financial press and each evening after 7:00 PM

(Eastern Time) by calling 800-GABELLI (800-422-3554). Please call us during the business day, between

8:00 AM – 7:00 PM (Eastern Time), for further information.

We welcome your comments and questions via e-mail at info@gabelli.com. You may sign up for our

e-mail alerts at www.gabelli.com and receive early notice of quarterly report availability, news events, media

sightings, and mutual fund prices and performance.

e-delivery

We are pleased to offer electronic delivery of Gabelli fund documents. Direct shareholders of our mutual

funds can elect to receive their Annual and Semiannual Reports, Manager Commentaries, and Prospectuses

via e-delivery. For more information or to sign up for e-delivery, please visit our website at www.gabelli.com.

Multi-Class Shares

GAMCO Global Series Funds, Inc. began offering additional classes of Fund shares in March 2000. Class

AAA Shares are no-load shares offered directly through selected broker/dealers. Class A and Class C Shares

are targeted to the needs of investors who seek advice through financial consultants. Class I Shares are

available directly through the Fund’s distributor or brokers that have entered into selling agreements specifically

with respect to Class I Shares. The Board of Directors determined that expanding the types of Fund shares

available through various distribution options would enhance the ability of the Fund to attract additional investors.

10

Gabelli/GAMCO Funds and Your Personal Privacy

Who are we?

The Gabelli/GAMCO Funds are investment companies registered with the Securities and ExchangeCommission under the Investment Company Act of 1940. We are managed by Gabelli Funds, LLC andGAMCO Asset Management Inc., which are affiliated with GAMCO Investors, Inc. GAMCO Investors,Inc. is a publicly held company that has subsidiaries that provide investment advisory services for avariety of clients.

What kind of non-public information do we collect about you if you become a fund shareholder?

If you apply to open an account directly with us, you will be giving us some non-public information aboutyourself. The non-public information we collect about you is:

• Information you give us on your application form. This could include your name, address,telephone number, social security number, bank account number, and other information.

• Information about your transactions with us, any transactions with our affiliates, andtransactions with the entities we hire to provide services to you. This would include informationabout the shares that you buy or redeem. If we hire someone else to provide services—like atransfer agent—we will also have information about the transactions that you conduct through them.

What information do we disclose and to whom do we disclose it?

We do not disclose any non-public personal information about our customers or former customers toanyone other than our affiliates, our service providers who need to know such information, and asotherwise permitted by law. If you want to find out what the law permits, you can read the privacy rulesadopted by the Securities and Exchange Commission. They are in volume 17 of the Code of FederalRegulations, Part 248. The Commission often posts information about its regulations on its website,www.sec.gov.

What do we do to protect your personal information?

We restrict access to non-public personal information about you to the people who need to know thatinformation in order to provide services to you or the fund and to ensure that we are complying with thelaws governing the securities business. We maintain physical, electronic, and procedural safeguards tokeep your personal information confidential.

Portfolio Management Team Biographies

Caesar M. P. Bryan joined GAMCO Asset Management in 1994. He is a member of the global investment team

of Gabelli Funds, LLC and portfolio manager of several funds within the Gabelli/GAMCO Funds Complex. Prior

to joining Gabelli, Mr. Bryan was a portfolio manager at Lexington Management. He began his investment

career in 1979 at Samuel Montagu Company, the London based merchant bank. Mr. Bryan graduated from the

University of Southampton in England with a Bachelor of Law and is a member of the English Bar.

Howard F. Ward, CFA, joined Gabelli Funds in 1995 and currently serves as GAMCO’s Chief Investment

Officer of Growth Equities as well as a Gabelli Funds, LLC portfolio manager for several funds within the

Gabelli/GAMCO Funds Complex. Prior to joining Gabelli, Mr. Ward served as Managing Director and Lead

Portfolio Manager for several Scudder mutual funds. He also was the Investment Officer in the Institutional

Investment Department with Brown Brothers, Harriman & Co. for four years. Mr. Ward received his B.A. in

Economics from Northwestern University.

THE GAMCO GLOBAL GROWTH FUndOne Corporate CenterRye, nY 10580-1422

GAMCO Global Series Funds, Inc.THE GAMCO GLOBAL GROWTH FUND One Corporate CenterRye, NY 10580-1422

t 800-GABELLI (800-422-3554)f 914-921-5118e info@gabelli.com

GABELL I .COM

Net Asset Value per share available dailyby calling 800-GABELLI after 7:00 P.M.

BOARD OF DIRECTORS

Mario J. Gabelli, CFAChairman and Chief Executive Officer,GAMCO Investors, Inc.Chairman and Chief Executive Officer,Associated Capital Group Inc.

E. Val CeruttiChief Executive Officer,Cerutti Consultants, Inc.

Anthony J. ColavitaPresident,Anthony J. Colavita, P.C.

Arthur V. FerraraFormer Chairman andChief Executive Officer,Guardian Life InsuranceCompany of America

John D. GabelliSenior Vice President,G.research, Inc.

Werner J. Roeder, MDFormer Medical Director,Lawrence Hospital

Anthonie C. van EkrisChairman,BALMAC International, Inc.Salvatore J. ZizzaChairman,Zizza & Associates Corp.

OFFICERSBruce N. AlpertPresidentAndrea R. MangoSecretaryAgnes MulladyTreasurerRichard J. WalzChief Compliance Officer

DISTRIBUTORG.distributors, LLC

CUSTODIAN, TRANSFER AGENT, AND DIVIDENDDISBURSING AGENTState Street Bank and TrustCompany

LEGAL COUNSELSkadden, Arps, Slate, Meagher &Flom LLP

This report is submitted for the general information of the shareholders of The GAMCO Global Growth Fund. It is notauthorized for distribution to prospective investors unlesspreceded or accompanied by an effective prospectus.

THEGAMCOGLOBALGROWTHFUND

Shareholder CommentarySeptember 30, 2016

GAB442Q316SC

Caesar M. P. Bryan Howard F. Ward, CFA

To Our Shareholders,

For the quarter ended September 30, 2016, the net asset value (“NAV”) per Class AAA Share of The GAMCOGlobal Growth Fund increased 4.6% compared with an increase of 5.3% for the Morgan Stanley Capital International(“MSCI”) All Country (“AC”) World Index. See page 2 for additional performance information.

Enclosed is the schedule of investments as of September 30, 2016.

The GAMCO Global Growth FundThird Quarter Report — September 30, 2016

(Y)our Portfolio Management Team

Comparative ResultsAverage Annual Returns through September 30, 2016 (a) (Unaudited)

Quarter 1 Year 5 Year 10 Year 15 Year

SinceInception(2/7/94)

Class AAA (GICPX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.57% 8.82% 13.15% 6.02% 6.93% 8.42%MSCI AC World Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.30 11.96 10.63 4.34 6.47 6.24(d)Lipper Global Large-Cap Growth Fund Classification . . . . . . . . . . . 5.36 10.41 11.32 5.21 6.49 7.02Class A (GGGAX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.57 8.84 13.17 6.02 6.94 8.43With sales charge (b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (1.45) 2.58 11.83 5.40 6.52 8.15Class C (GGGCX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.38 8.02 12.31 5.23 6.13 7.83With contingent deferred sales charge (c) . . . . . . . . . . . . . . . . . . . 3.38 7.02 12.31 5.23 6.13 7.83Class I (GGGIX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.77 9.64 13.66 6.37 7.17 8.58In the current prospectuses dated April 29, 2016, the gross expense ratios for Class AAA, A, C, and I Shares are 1.68%, 1.68%, 2.43%, and1.43%, respectively, and the net expense ratios for these share classes after contractual reimbursements by Gabelli Funds, LLC, (the“Adviser”) are 1.68%, 1.68%, 2.43%, and 1.00%, respectively. Class AAA and Class I Shares do not have a sales charge. The maximum salescharge for Class A Shares and Class C Shares is 5.75% and 1.00%, respectively.(a) Returns represent past performance and do not guarantee future results. Total returns and average annual returns reflect changes in share price,

reinvestment of distributions, and are net of expenses. Investment returns and the principal value of an investment will fluctuate. When shares areredeemed, they may be worth more or less than their original cost. Current performance may be lower or higher than the performance datapresented. Visit www.gabelli.com for performance information as of the most recent month end. Returns for Class I Shares would have been lowerhad the Adviser not reimbursed certain expenses. The Fund imposes a 2% redemption fee on shares sold or exchanged within seven days after thedate of purchase. Performance returns for periods of less than one year are not annualized. Investors should carefully consider the investmentobjectives, risks, charges, and expenses of the Fund before investing. The prospectuses contain information about these and other matters andshould be read carefully before investing. To obtain a prospectus, please visit our website at www.gabelli.com. Investing in foreign securitiesinvolves risks not ordinarily associated with investments in domestic issues, including currency fluctuation, economic, and political risks. TheClass AAA Share NAVs are used to calculate performance for the periods prior to the issuance of Class A Shares, Class C Shares, and Class IShares on March 2, 2000, March 12, 2000, and January 11, 2008, respectively. The actual performance of the Class A and Class C Shares wouldhave been lower due to the additional fees and expenses associated with these classes of shares. The actual performance of Class I Shares wouldhave been higher due to lower expenses related to this class of shares. The MSCI AC World Index is an unmanaged market capitalization weightedindex that is designed to measure the equity market performance of developed and emerging markets. The MSCI AC World Index consists of 45country indices comprising 24 developed and 21 emerging market country indices. The Lipper Global Large-Cap Growth Fund Classification reflectsthe performance of mutual funds classified in this particular category. Dividends are considered reinvested. You cannot invest directly in an index.

(b) Performance results include the effect of the maximum 5.75% sales charge at the beginning of the period.(c) Assuming payment of the 1% maximum contingent deferred sales charge imposed on redemptions made within one year of purchase.(d) MSCI AC World Index since inception performance is a blend of Gross Performance excluding applicable taxes and Net Performance. This

benchmark’s Net Performance began on December 29, 2000.

2

SharesMarketValue

COMMON STOCKS — 97.4%INFORMATION TECHNOLOGY — 24.6%

16,900 Adobe Systems Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 1,834,326810 Alphabet Inc., Cl. A† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651,289

2,701 Alphabet Inc., Cl. C† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,099,46013,510 Apple Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,527,30623,300 Facebook Inc., Cl. A†. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,988,6915,700 Fiserv Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566,9792,900 Keyence Corp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,124,8008,600 MasterCard Inc., Cl. A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 875,222

41,700 Microsoft Corp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,401,9202,600 Palo Alto Networks Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . . 414,258

15,000 Sabre Corp.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422,7005,300 salesforce.com Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378,049

60,200 Tencent Holdings Ltd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,673,6835,600 Texas Instruments Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393,008

17,000 Visa Inc., Cl. A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,405,90019,757,591

CONSUMER DISCRETIONARY — 24.0%2,890 Amazon.com Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,419,826

600 AutoZone Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461,00410,700 CBS Corp., Cl. B, Non-Voting . . . . . . . . . . . . . . . . . . . . . . 585,7181,440 Chipotle Mexican Grill Inc.† . . . . . . . . . . . . . . . . . . . . . . . 609,8402,000 Christian Dior SE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358,695

18,600 Comcast Corp., Cl. A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,233,9243,114 Compagnie Financiere Richemont SA. . . . . . . . . . . . . . 189,915

17,800 Fuji Heavy Industries Ltd. . . . . . . . . . . . . . . . . . . . . . . . . . 667,847448,000 ITV plc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,086,71849,800 Liberty Global plc, Cl. A† . . . . . . . . . . . . . . . . . . . . . . . . . . 1,702,1646,000 Lululemon Athletica Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . 365,880

16,600 Luxottica Group SpA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 792,8724,900 LVMH Moet Hennessy Louis Vuitton SE . . . . . . . . . . . 835,5088,500 NIKE Inc., Cl. B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447,5251,000 O’Reilly Automotive Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . 280,110

11,900 ProSiebenSat.1 Media SE . . . . . . . . . . . . . . . . . . . . . . . . . 510,2177,000 Shake Shack Inc., Cl. A† . . . . . . . . . . . . . . . . . . . . . . . . . . 242,690

13,300 Starbucks Corp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720,0627,000 The Home Depot Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900,760

240 The Priceline Group Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . 353,15814,500 The Swatch Group AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 807,3495,000 The TJX Companies Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . 373,9005,600 The Walt Disney Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520,016

15,100 Time Warner Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,202,11112,100 Twenty-First Century Fox Inc., Cl. A. . . . . . . . . . . . . . . . 293,0622,000 Ulta Salon Cosmetics & Fragrance Inc.† . . . . . . . . . . . 475,960

36,600 WPP plc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 860,30119,297,132

CONSUMER STAPLES — 14.1%12,000 Blue Buffalo Pet Products Inc.† . . . . . . . . . . . . . . . . . . . 285,1202,400 Costco Wholesale Corp.. . . . . . . . . . . . . . . . . . . . . . . . . . . 366,024

10,900 CVS Health Corp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 969,991

SharesMarketValue

40,000 Davide Campari-Milano SpA. . . . . . . . . . . . . . . . . . . . . . . $ 450,78027,500 Diageo plc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 787,6949,600 Henkel AG & Co. KGaA. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,119,6927,400 L’Oreal SA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,398,678

20,600 Nestlé SA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,626,6605,156 Pernod Ricard SA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610,650

13,100 Reckitt Benckiser Group plc . . . . . . . . . . . . . . . . . . . . . . . 1,233,29213,300 Seven & i Holdings Co. Ltd. . . . . . . . . . . . . . . . . . . . . . . . 628,7615,000 Sprouts Farmers Market Inc.† . . . . . . . . . . . . . . . . . . . . . 103,2503,200 The Estee Lauder Companies Inc., Cl. A. . . . . . . . . . . . 283,3929,900 Unicharm Corp.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256,881

15,000 Walgreens Boots Alliance Inc. . . . . . . . . . . . . . . . . . . . . . 1,209,30011,330,165

HEALTH CARE — 11.2%1,600 Amgen Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266,8964,400 Becton, Dickinson and Co. . . . . . . . . . . . . . . . . . . . . . . . . 790,812

800 Biogen Inc.† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250,42415,400 Bristol-Myers Squibb Co. . . . . . . . . . . . . . . . . . . . . . . . . . 830,3684,600 Celgene Corp.† . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480,8385,900 Danaher Corp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462,5016,800 Essilor International SA . . . . . . . . . . . . . . . . . . . . . . . . . . . 877,1747,500 Johnson & Johnson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 885,975

10,000 Roche Holding AG, ADR . . . . . . . . . . . . . . . . . . . . . . . . . . 309,7002,600 Roche Holding AG, Genusschein . . . . . . . . . . . . . . . . . . 646,096

60,400 Smith & Nephew plc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 974,1493,200 Thermo Fisher Scientific Inc. . . . . . . . . . . . . . . . . . . . . . . 508,9926,200 UnitedHealth Group Inc.. . . . . . . . . . . . . . . . . . . . . . . . . . . 868,000

15,400 Zoetis Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800,9548,952,879

INDUSTRIALS — 9.8%3,000 3M Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528,690

35,000 CK Hutchison Holdings Ltd. . . . . . . . . . . . . . . . . . . . . . . . 447,3793,700 FANUC Corp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624,9872,100 FedEx Corp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366,8287,600 Fortune Brands Home & Security Inc. . . . . . . . . . . . . . 441,560

24,300 General Electric Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 719,7666,800 Honeywell International Inc. . . . . . . . . . . . . . . . . . . . . . . . 792,812

19,500 Jardine Matheson Holdings Ltd. . . . . . . . . . . . . . . . . . . . 1,183,5868,500 Nielsen Holdings plc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455,3457,700 Secom Co. Ltd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574,9926,900 Siemens AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 809,1003,700 Snap-on Inc.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562,2522,500 The Boeing Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329,350

7,836,647

ENERGY — 5.2%22,500 BP plc, ADR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791,10017,800 EOG Resources Inc.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,721,43821,500 Schlumberger Ltd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,690,760

4,203,298

The GAMCO Global Growth FundSchedule of Investments — September 30, 2016 (Unaudited)

See accompanying notes to schedule of investments.

3

SharesMarketValue

COMMON STOCKS (Continued)MATERIALS — 4.3%

10,900 Air Liquide SA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 1,168,8843,300 Ecolab Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401,6767,400 PPG Industries Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 764,8643,900 The Sherwin-Williams Co.. . . . . . . . . . . . . . . . . . . . . . . . . 1,078,974

3,414,398

FINANCIALS — 4.2%7,000 First Republic Bank/CA. . . . . . . . . . . . . . . . . . . . . . . . . . . . 539,770

12,900 HDFC Bank Ltd., ADR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 927,38113,300 JPMorgan Chase & Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . 885,64719,300 Schroders plc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 673,97810,100 The Charles Schwab Corp. . . . . . . . . . . . . . . . . . . . . . . . . 318,857

3,345,633

TOTAL COMMON STOCKS . . . . . . . . . . . . . . . . . . . . . . . . 78,137,743

PrincipalAmount

U.S. GOVERNMENT OBLIGATIONS — 2.6%$ 2,105,000 U.S. Treasury Bills,

0.120% to 0.451%††, 12/08/16 to 03/16/17. . . . 2,102,325

TOTAL INVESTMENTS — 100.0%(Cost $63,026,450) . . . . . . . . . . . . . . . . . . . . . . . . $80,240,068

MarketValue

Aggregate tax cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $63,203,929

Gross unrealized appreciation . . . . . . . . . . . . . . . . . . . . . $18,441,452Gross unrealized depreciation . . . . . . . . . . . . . . . . . . . . . (1,405,313)Net unrealized appreciation/depreciation . . . . . . . . . . . $17,036,139

† Non-income producing security.†† Represents annualized yield at date of purchase.ADR American Depositary Receipt

Geographic Diversification

% ofMarketValue

MarketValue

United States. . . . . . . . . . . . . . . . . . 60.3% $48,362,299Europe . . . . . . . . . . . . . . . . . . . . . 26.3 21,076,713Latin America . . . . . . . . . . . . . . . . . 6.2 4,995,407Japan . . . . . . . . . . . . . . . . . . . . . . 6.1 4,878,268Asia/Pacific. . . . . . . . . . . . . . . . . . . 1.1 927,381

100.0% $80,240,068

The GAMCO Global Growth FundSchedule of Investments (Continued) — September 30, 2016 (Unaudited)

See accompanying notes to schedule of investments.

4

As an investment company, the Fund follows the investment company accounting and reporting guidance,which is part of U.S. generally accepted accounting principles (“GAAP”) that may require the use of managementestimates and assumptions in the preparation of its schedule of investments. Actual results could differ fromthose estimates. The following is a summary of significant accounting policies followed by the Fund in thepreparation of its schedule of investments.

Security Valuation. Portfolio securities listed or traded on a nationally recognized securities exchange or tradedin the U.S. over-the-counter market for which market quotations are readily available are valued at the lastquoted sale price or a market’s official closing price as of the close of business on the day the securities arebeing valued. If there were no sales that day, the security is valued at the average of the closing bid and askedprices or, if there were no asked prices quoted on that day, then the security is valued at the closing bid priceon that day. If no bid or asked prices are quoted on such day, the security is valued at the most recentlyavailable price or, if the Board of Directors (the “Board”) so determines, by such other method as the Boardshall determine in good faith to reflect its fair market value. Portfolio securities traded on more than one nationalsecurities exchange or market are valued according to the broadest and most representative market, as determinedby Gabelli Funds, LLC (the “Adviser”).

Portfolio securities primarily traded on a foreign market are generally valued at the preceding closing valuesof such securities on the relevant market, but may be fair valued pursuant to procedures established by theBoard if market conditions change significantly after the close of the foreign market, but prior to the close ofbusiness on the day the securities are being valued. Debt instruments with remaining maturities of sixty daysor less that are not credit impaired are valued at amortized cost, unless the Board determines such amountdoes not reflect the securities’ fair value, in which case these securities will be fair valued as determined bythe Board. Debt instruments having a maturity greater than sixty days for which market quotations are readilyavailable are valued at the average of the latest bid and asked prices. If there were no asked prices quotedon such day, the security is valued using the closing bid price. U.S. government obligations with maturitiesgreater than sixty days are normally valued using a model that incorporates market observable data such asreported sales of similar securities, broker quotes, yields, bids, offers, and reference data. Certain securitiesare valued principally using dealer quotations.

Securities and assets for which market quotations are not readily available are fair valued as determined bythe Board. Fair valuation methodologies and procedures may include, but are not limited to: analysis and reviewof available financial and non-financial information about the company; comparisons with the valuation andchanges in valuation of similar securities, including a comparison of foreign securities with the equivalent U.S.dollar value American Depositary Receipt securities at the close of the U.S. exchange; and evaluation of anyother information that could be indicative of the value of the security.

The Fund employs a fair value model to adjust prices to reflect events affecting the values of certain portfoliosecurities which occur between the close of trading on the principal market for such securities (foreign exchangesand over-the-counter markets) at the time when net asset values of the Fund are determined. If the Fund’svaluation committee believes that a particular event would materially affect net asset value, further adjustmentis considered.

The GAMCO Global Growth FundNotes to Schedule of Investments (Unaudited)

5

The inputs and valuation techniques used to measure fair value of the Fund’s investments are summarizedinto three levels as described in the hierarchy below:

• Level 1 — quoted prices in active markets for identical securities;• Level 2 — other significant observable inputs (including quoted prices for similar securities, interest

rates, prepayment speeds, credit risk, etc.); and• Level 3 — significant unobservable inputs (including the Board’s determinations as to the fair value

of investments).

A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input bothindividually and in the aggregate that is significant to the fair value measurement. The inputs or methodologyused for valuing securities are not necessarily an indication of the risk associated with investing in those securities.The closing price is adjusted from the local close, therefore, such securities are classified as Level 2 in thefair value hierarchy presented below. The summary of the Fund’s investments in securities by inputs used tovalue the Fund’s investments as of September 30, 2016 is as follows:

Valuation InputsLevel 1

Quoted PricesLevel 2 Other Significant

Observable InputsTotal Market Value

at 9/30/16INVESTMENTS IN SECURITIES:ASSETS (Market Value):

Common Stocks:Information Technology $15,959,108 $ 3,798,483 $19,757,591Consumer Discretionary 13,187,710 6,109,422 19,297,132Consumer Staples 3,217,077 8,113,088 11,330,165Health Care 6,455,460 2,497,419 8,952,879Industrials 4,196,603 3,640,044 7,836,647Energy 4,203,298 — 4,203,298Materials 2,245,514 1,168,884 3,414,398Financials 2,671,655 673,978 3,345,633

Total Common Stocks 52,136,425 26,001,318 78,137,743U.S. Government Obligations — 2,102,325 2,102,325

TOTAL INVESTMENTS IN SECURITIES – ASSETS $52,136,425 $28,103,643 $80,240,068

Additional Information to Evaluate Qualitative Information.

General. The Fund uses recognized industry pricing services – approved by the Board and unaffiliated withthe Adviser – to value most of its securities, and uses broker quotes provided by market makers of securitiesnot valued by these and other recognized pricing sources. Several different pricing feeds are received to valuedomestic equity securities, international equity securities, preferred equity securities, and fixed income securities.The data within these feeds is ultimately sourced from major stock exchanges and trading systems where thesesecurities trade. The prices supplied by external sources are checked by obtaining quotations or actual transactionprices from market participants. If a price obtained from the pricing source is deemed unreliable, prices will besought from another pricing service or from a broker/dealer that trades that security or similar securities.

Fair Valuation. Fair valued securities may be common and preferred equities, warrants, options, rights,and fixed income obligations. Where appropriate, Level 3 securities are those for which market quotations arenot available, such as securities not traded for several days, or for which current bids are not available, orwhich are restricted as to transfer. Among the factors to be considered to fair value a security are recent pricesof comparable securities that are publicly traded, reliable prices of securities not publicly traded, the use of

The GAMCO Global Growth FundNotes to Schedule of Investments (Unaudited) (Continued)

6

valuation models, current analyst reports, valuing the income or cash flow of the issuer, or cost if the precedingfactors do not apply. The circumstances of Level 3 securities are frequently monitored to determine if fair valuationmeasures continue to apply.

The Adviser reports quarterly to the Board the results of the application of fair valuation policies and procedures.These may include back testing the prices realized in subsequent trades of these fair valued securities to fairvalues previously recognized.

Foreign Currency Translations. The books and records of the Fund are maintained in U.S. dollars. Foreigncurrencies, investments, and other assets and liabilities are translated into U.S. dollars at current exchangerates. Purchases and sales of investment securities, income, and expenses are translated at the exchangerate prevailing on the respective dates of such transactions. Unrealized gains and losses that result from changesin foreign exchange rates and/or changes in market prices of securities have been included in unrealizedappreciation/depreciation on investments and foreign currency translations. Net realized foreign currency gainsand losses resulting from changes in exchange rates include foreign currency gains and losses between tradedate and settlement date on investment securities transactions, foreign currency transactions, and the differencebetween the amounts of interest and dividends recorded on the books of the Fund and the amounts actuallyreceived. The portion of foreign currency gains and losses related to fluctuation in exchange rates betweenthe initial purchase trade date and subsequent sale trade date is included in realized gain/(loss) on investments.

Foreign Securities. The Fund may directly purchase securities of foreign issuers. Investing in securities offoreign issuers involves special risks not typically associated with investing in securities of U.S. issuers. Therisks include possible revaluation of currencies, the inability to repatriate funds, less complete financial informationabout companies, and possible future adverse political and economic developments. Moreover, securities ofmany foreign issuers and their markets may be less liquid and their prices more volatile than securities ofcomparable U.S. issuers.

Foreign Taxes. The Fund may be subject to foreign taxes on income, gains on investments, or currency repatriation,a portion of which may be recoverable. The Fund will accrue such taxes and recoveries as applicable, basedupon its current interpretation of tax rules and regulations that exist in the markets in which it invests.

Tax Information. The Fund intends to continue to qualify as a regulated investment company under Subchapter Mof the Internal Revenue Code of 1986, as amended.

The GAMCO Global Growth FundNotes to Schedule of Investments (Unaudited) (Continued)

7

THE GAMCO GLOBAL GROWTH FUNDOne Corporate CenterRye, NY 10580-1422

Portfolio Management Team Biographies

Caesar M. P. Bryan joined GAMCO Asset Management in 1994. He is a member of the global investment teamof Gabelli Funds, LLC and portfolio manager of several funds within the Gabelli/GAMCO Fund Complex. Prior tojoining Gabelli, Mr. Bryan was a portfolio manager at Lexington Management. He began his investment career atSamuel Montagu Company, the London based merchant bank. Mr. Bryan graduated from the University of Southamptonin England with a Bachelor of Law and is a member of the English Bar.

Howard F. Ward, CFA, joined Gabelli Funds in 1995 and currently serves as GAMCO’s Chief Investment Officerof Growth Equities as well as a Gabelli Funds, LLC portfolio manager for several funds within the Gabelli/GAMCOFund Complex. Prior to joining Gabelli, Mr. Ward served as Managing Director and Lead Portfolio Manager forseveral Scudder mutual funds. He also was an Investment Officer in the Institutional Investment Department withBrown Brothers, Harriman & Co. for four years. Mr. Ward received his B.A. in Economics from NorthwesternUniversity.

We have separated the portfolio managers’ commentary from the financial statements and investment portfolio due tocorporate governance regulations stipulated by the Sarbanes-Oxley Act of 2002. We have done this to ensure that thecontent of the portfolio managers’ commentary is unrestricted. The financial statements and investment portfolio aremailed separately from the commentary. Both the commentary and the financial statements, including the portfolio ofinvestments, will be available on our website at www.gabelli.com.

GAMCO Global Series Funds, Inc.

THE GAMCO GLOBAL GROWTH FUNDOne Corporate CenterRye, New York 10580-1422

t 800-GABELLI (800-422-3554)f 914-921-5118e info@gabelli.com

GABELLI.com

Net Asset Value per share available dailyby calling 800-GABELLI after 7:00 P.M.

BOARD OF DIRECTORSMario J. Gabelli, CFAChairman andChief Executive Officer,GAMCO Investors, Inc.Chairman andChief Executive Officer,Associated Capital Group, Inc.

E. Val CeruttiChief Executive Officer,Cerutti Consultants, Inc.

Anthony J. ColavitaPresident,Anthony J. Colavita, P.C.

Arthur V. FerraraFormer Chairman andChief Executive Officer,Guardian Life InsuranceCompany of America

John D. GabelliSenior Vice President,G.research, LLC

Werner J. Roeder, MDFormer Medical Director,Lawrence Hospital

Anthonie C. van EkrisChairman,BALMAC International, Inc.

Salvatore J. ZizzaChairman,Zizza & Associates Corp.

OFFICERS

Bruce N. AlpertPresident

Andrea R. MangoSecretary

Agnes MulladyTreasurer

Richard J. WalzChief Compliance Officer

DISTRIBUTORG.distributors, LLC

CUSTODIAN, TRANSFERAGENT, AND DIVIDENDDISBURSING AGENTState Street Bank and TrustCompany

LEGAL COUNSELSkadden, Arps, Slate, Meagher &Flom LLP

This report is submitted for the general information of the shareholdersof The GAMCO Global Growth Fund. It is not authorized for distributionto prospective investors unless preceded or accompanied by an effectiveprospectus.

THEGAMCOGLOBAL GROWTHFUND

Third Quarter ReportSeptember 30, 2016

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