What are options? - 4FM3 - homeCollege+of... · · 2011-01-17What are options? ð§A financial...
Transcript of What are options? - 4FM3 - homeCollege+of... · · 2011-01-17What are options? ð§A financial...
What are options?
A financial derivative contract thatprovides a party the right to buy or sell butnot the obligation an underlying at a fixedprice by a certain time in the future
Types of Options
Call Option An option granting the
right to buy theunderlying
Put Option An option granting the
right to sell theunderlying
Characteristics of Options
Option price, option premium, orpremium
the amount of money a buyer pays andseller receives to engage in an optiontransaction
Characteristics of Options
Exercise price, strike price, striking price,or strike
the fixed price at which the option holdercan buy or sell the underlying
Characteristics of Options
Time to expiration
the time remaining inthe life of aderivative, typicallyexpressed in years
Option Pricing Dates
Premium Payment Date Day when option
premium has to bepaid
Usually two bankingdays after the tradingdate
Concept of Moneyness of an Option In-the-money
Option that, ifexercised, wouldresult in the valuereceived beingworth more than thepayment required toexercise
Concept of Moneyness of an Option At-the-money
Option in which the underlyingvalue equals the exercise price
Concept of Moneyness of an Option Out-of-the money
Option that, ifexercised wouldrequire the payment ofmore money than thevalue received andtherefore would not becurrently exercised
Characteristics of Options
European option
An option that canbe exercised only atexpiration
Also referred to asEuropean styleexercise
Characteristics of Options
American option
An option that can beexercised on any daythrough the expiration day
Also referred to asAmerican style exercise
Types of Financial Options
Bond Options
Options in which theunderlying is a bond
Primarily traded inover-the-countermarkets
Types of Financial Options
Currency Options
Options that allow theholder to buy (if a call) orsell (if a put) anunderlying currency at afixed exercise rate,expressed as anexchange rate
Types of Financial Options
Options on futures
Options that give theholder the right toenter into a longfutures contract at afixed futures price
Currency Option P/L ProfileBuyer of a Call
Profit (Loss) = spot rate – (strike price + premium)
Write (seller) of a CallProfit (Loss) = premium – (spot rate – strike price)
Buyer of a PutProfit (Loss) = strike price – (spot price + premium)
Writer (Seller) of a PutProfit (Loss) = premium – (strike price – spot rate)
Option Pricing Sensitivities (The Greek Chorus)
Delta – Spot Rate Sensitivity
Delta (Δ) = Δ premiumΔ spot rate
As the option moves further ITM, delta risestowards 1.0.
As the option moves further OTM, delta fallstowards zero.
The higher the delta (around 0.7, 0.8 or higher),the greater the probability of the option expiringin the money.
Option Pricing Sensitivities (The Greek Chorus)
Theta – Sensitivity to Time to Maturity
Theta (θ) = Δ premiumΔ time
Option values increase the longer it is to maturity.
Longer maturity options have better values because it gives thetrader the ability to change his option position without losingsignificant time value deterioration.
Option premiums deteriorate at an increasing rate as theyapproach expiration.
Theta is not based on a linear relationship with time, but ratherthe square of time.
Option Pricing Sensitivities (The Greek Chorus)
Vega – Sensitivity to Volatility
Vega = Δ premiumΔ volatility
If volatilities will fall sharply in the near term,traders will write (sell) options now, hoping tobuy them back for a profit right after volatilitiesfall.
This action causes option prices to fall.
Option Pricing Sensitivities (The Greek Chorus)
Rho – Sensitivity to Change in DomesticInterest Rates
Rho (ρ) = Δ premiumΔ Domestic Interest Rate
A call option on foreign currency shouldbe bought before a rise in domesticinterest rates before the option price willincrease.
Option Pricing Sensitivities (The Greek Chorus)
Phi – Sensitivity to Change in ForeignInterest Rates
Phi (Φ) = Δ premiumΔ Foreign Interest Rate
Payoff of OptionsCall Option
At expiration, a call option is worth eitherzero or the difference between the underlyingprice S and the exercise price X, whicheveris greater
Payoff has to be positive to be exercised
Payoff = max [0, S - X]
Payoff of OptionsPut Option
At expiration, a put option is worth eitherzero or the difference between the exerciseprice X and the underlying price S,whichever is greater
Payoff has to be positive to be exercised
Payoff = max [0, X - S]
Minimum and Maximum Values of Options
• The maximum value of a European put isthe present value of the exercise price.
• The maximum value of an American put isthe exercise price.
Option Pricing and Valuation Determinants
Time Value
Intrinsic Value
Time Value = Option Premium less Intrinsic Value
Call Option = Spot Price less Strike PricePut Option = Strike Price less Spot Price
Intrinsic Value – financial gain if the option is exercisedimmediately.
Time Value – value of an option arising from the time left tomaturity.
Factors Affecting Option Price
Time Value
Intrinsic Value
OptionPremium
StrikePrice
OutrightForward
Rates
Term
Volatility
Three Types of Volatility
Historic Volatility
Standard deviation ofthe continuouslycompounded returnon an asset estimatedfrom historical data
Three Types of Volatility
Forward-LookingVolatility
Recent historicvolatility adjusted forexpected marketoutlook
Three Types of Volatility
Implied Volatility
Volatility implied froman option price usingBlack-Scholes that willequal the observedmarket price of theoption
Black-Scholes-Merton Model A model for pricing European options on stocks,
developed by Fischer Black, Myron Scholes, and RobertMerton in 1973.
c = S0 N(d1) – X e-rT N(d2)p = X e-rT [1 - (d2)] – S[1 - N(d1)]
whered1= ln(S/X) + [rc + (σ/2)]T / σ √ Td2 = d1 - σ √ Tσ = annualized standard deviation of the continuously
compounded return on the stockrc = continuously compounded risk-free rate of returnT = timeN( ) = Cumulative Normal DistributionFunction
Put-Call Parity
c0 + X / ( 1 + r )t = p0 + S0
Where:c0 = European call optionp0 = European put optionX = risk free bondS0 = the underlying assetr = annual interest ratet = time in years
Put-Call Parity
An equation expressingthe equivalence (parity)of a portfolio of a call anda bond with a portfolio ofa put and the underlying,which leads to therelationship between putand call prices
Pricing Options
Binomial Model – a model for pricingoptions in which the underlying price canmove to only one of two possible newprices
It’s used for discrete time option pricing Binomial tree – a diagram representing
price movements of the underlying in abinomial model
Kinds of Binomial Models
One Period Binomial Model Two Period Binomial Model N period Binomial Model
Assumptions of Binomial Option PricingModel
• Market is frictionless• Investors are price takers• Short selling is allowed, with full use of
proceeds• Borrowing and lending at the risk free rate
is permitted• Future stock prices will have one or two
possible values
Synthetic Forward Contract
A contract consisting of a long call, a shortput, and a long risk free bond with a facevalue equal to the exercise price minus theforward price.
Black Model
• Model for pricing European options onfutures.
• Used frequently to price interest rateoptions.