Upload
avis-atkins
View
215
Download
0
Embed Size (px)
Citation preview
11
Chapter 11Chapter 11 Options – Derivative Options – Derivative
SecuritiesSecurities
22Copyright © 1998 by Harcourt Brace & Company
Student Learning Student Learning ObjectivesObjectives
Basic Option Terminology Characteristics of option contracts Option values Common option trading strategies Option valuation Other securities that resemble
options
33
Characteristics of Option Characteristics of Option ContractsContracts
Option contracts give the holder the right but not the obligation to: – buy or sell a stated number of shares (100) – at a specified price (exercise or strike price) – until a specified point in time (expiration
date) An option to buyoption to buy stock is a callcall option An option to selloption to sell stock is a putput option Options are called derivatives securitiesderivatives securities
because their value is derived from the value of the underlying security.
44
Writing an OptionWriting an Option
The person who sells an option (writeswrites an option) receives a “premium”– the premium is the current market value of
the option and includes: time value intrinsic value (if in-the-money)
– Option Writer is said to be “short” Covered Call Writer – owns stock Naked Call Writer – does not own stock If Exercised – writer must deliver stock
to option call buyer
55
Call OptionsCall Options
“In-the-moneyIn-the-money”: stock price exceeds the exercise price
“at-the-moneyat-the-money”: stock price equals the exercise price it is
“Out-of-the-moneyOut-of-the-money”: stock price is less than the exercise price
The option buyer has a “long position”
The option seller (writer) has a “short position”
66
Put OptionsPut Options
“In-the-moneyIn-the-money”: stock price less than the exercise price
“at-the-moneyat-the-money”: stock price equals the exercise price
“Out-of-the-moneyOut-of-the-money”: stock price is greater than the exercise price
Naked PutsNaked Puts – not protecting a long stock position
Married PutsMarried Puts – protecting a long stock position
77
Option ExpectationsOption Expectations
Call options bought by investors that expect prices to rise [relatively soon].
Put options bought by investors that expect price to decline. [ditto]
Call options sold by investors that expect prices to decline [soon].
Put options sold by investors that expect prices to rise [soon].
For every option traded there is both a long and a short position
88
Option ValueOption Value
Option values:– Intrinsic valueIntrinsic value is the difference
between the stock price and the exercise price
zero if the option is not “in-the-money.” can never be negative.
– Time valueTime value is the difference between the intrinsic value and the price of the option.
99
Call Option Value at ExpirationCall Option Value at Expiration
Value at expiration depends on price of underlying stock– If stock price is less than or equal to
the exercise price, then call option is worthless.
– If stock price is more than exercise price, a call option is “in-the-money”.
May be sold for the profit or exercised to obtain the stock by paying
the exercise or strike price.
1010
Expiration Date & ExerciseExpiration Date & Exercise
Saturday following third Friday of stated month in standard stock option contracts (last trade day is Friday!)
American: exercisable up till expiration
European: exercisable only on expiration
Bermuda: exercisable on multiple dates
1111
Profit and Loss From an Profit and Loss From an OptionOption
The profit and loss for an option writer and buyer are complements.– The expense of buying an option is
income to the writer/seller.– The profit/loss of the buyer is
opposite of the profit/loss of the seller and the net sum of the buyer and seller profit/loss is zero.
In a zero sum gamezero sum game, in order for one to make money, another must lose
1212
Option TradingOption Trading
Options are traded using market or limit orders.
Organized trading on exchanges has certain advantages over OTC trading:– Standardized contracts– Increased liquidity– More comprehensive disclosure and
surveillance– Guaranteed clearing of contracts– Lower transaction costs
1313
Options on Other SecuritiesOptions on Other Securities
Index optionsIndex options are calls or puts based on a stock market index, settled by settled by cashcash rather than delivery of underlying securities
Foreign currency optionsForeign currency options allow the holder to buy or sell a quantity of foreign currency for a specified amount of U. S. Dollars
Long-term optionsLong-term options, called LEAPS® have expiration dates up to two years from the date of issue
1414
Option Risks and Option Risks and OpportunitiesOpportunities
Options can be used to hedgeto hedge [reduce risk of long or short] stock positions or to speculateor to speculate.
Options trading provides leverage opportunities, similar to margin
Leverage is a double-edged sword, and can result in total loss of the cost of an option
1515
Call Option StrategiesCall Option Strategies
CALLCALL Strategy based on expectationsexpectations:– Call buyers expect market to go up:
Sellers expect market to go down or sideways.
– BuyerBuyer: deep out-of-the-money or short time period to expiration options have a greater potential return and increased risk of losing premiums paid.
– SellerSeller: at the money or long duration options have greater potential returns and greater risk of loss. Especially Naked writers.
1616
Put Option StrategiesPut Option Strategies
PUTPUT Strategy based on expectationsexpectations::– Put buyers expect market to go down:
Sellers expect market to go up or sideways.
– BuyerBuyer: deep out-of-the-money or short time period to expiration options have a greater potential return and greater risk.
– SellerSeller: near at-the money or long time period to expiration have more profit potential and greater risk of loss.
1717
Combining Option Combining Option and Stock Positionsand Stock Positions
Options can be used to provide income and reduce loss on a long stock position.– Writing a covered call: increase income on
owned stock, & reduces some downside loss.
– A protective put: Buying put options on owned stock reduce downside loss.
– A covered short sale: Buying call options on stock sold short to reduce position risk.
1818
Writing Naked CallsWriting Naked Calls
High risk Call Option [Speculation]:– Writing a naked call: Writing calls on
stock not owned - very risky play if writer is wrong about future direction.
1919
Determinants of Option Determinants of Option ValuesValues
Option’s value function of Option’s value function of – stock pricestock price– strike pricestrike price– stock return volatilitystock return volatility– riskless interest rate (t-bill rate)riskless interest rate (t-bill rate)– length of time to expirationlength of time to expiration
2020
Determinants of Option Determinants of Option ValuesValues
Stock Price:Stock Price: higher the stock price, more higher the stock price, more valuable the call.valuable the call.
Strike price:Strike price: higher the strike price, less higher the strike price, less valuable the call.valuable the call.
Volatility:Volatility: more volatile price of more volatile price of underlying stock, more valuable the underlying stock, more valuable the call.call.
Interest rate:Interest rate: higher the interest rate, higher the interest rate, more valuable the call.more valuable the call.
Time to maturity:Time to maturity: longer time to longer time to maturity, more valuable callmaturity, more valuable call
2121
Models for Valuing OptionsModels for Valuing Options
Black-Scholes option pricing modelBlack-Scholes option pricing model Binomial option pricing modelBinomial option pricing model Put-call parityPut-call parity
2222Copyright © 1998 by Harcourt Brace & Company
Black-Scholes Option Pricing Black-Scholes Option Pricing ModelModel
Assumes that a riskless hedge Assumes that a riskless hedge between an option and its between an option and its underlying stock should yield the underlying stock should yield the riskless return. riskless return.
2323
Hedge RatioHedge Ratio
In Black-Scholes model, number of In Black-Scholes model, number of calls written that would exactly calls written that would exactly offset stock price movement of offset stock price movement of number of shares of underlying number of shares of underlying stock held.stock held.– Small move in stock’s price would be Small move in stock’s price would be
precisely offset by change in value of precisely offset by change in value of option position with ratio of number option position with ratio of number of calls to number of shares of stockof calls to number of shares of stock
– Investor theoretically holding Investor theoretically holding equivalent of risk-free asset.equivalent of risk-free asset.
2424
Binomial OPMBinomial OPM
Simple model assumesSimple model assumes– price at end of period will be one of price at end of period will be one of
two values (basis for “Bi” in Binomial)two values (basis for “Bi” in Binomial)– alternative to call option is to borrow alternative to call option is to borrow
enough so to buy one share of stock enough so to buy one share of stock and just breakeven if stock closes at and just breakeven if stock closes at lower pricelower price
– Price of call option will be based on Price of call option will be based on how many calls are necessary to how many calls are necessary to duplicate loan strategy, and equity to duplicate loan strategy, and equity to set up loanset up loan
2525
Put-Call ParityPut-Call Parity
CC0 0 = P = P00 + S + S00 – X – X e errff t t
CC00 = call value= call value
PP00 = put value= put valuerrff = risk-free rate= risk-free rateee = 2.718 (the natural logarithmic constant)= 2.718 (the natural logarithmic constant)SS00 = initial stock price= initial stock priceXX = strike price= strike pricett = time to expiration as a fraction of a year= time to expiration as a fraction of a year
2626
Simple Positions and Simple Positions and SyntheticSynthetic EquivalentsEquivalents
Simple PositionSimple Position Synthetic EquivalentSynthetic Equivalent Long StockLong Stock Long a Call & Short a PutLong a Call & Short a Put Short StockShort Stock Short a Call & Long a PutShort a Call & Long a Put Long a CallLong a Call Long Stock & Long a PutLong Stock & Long a Put Short a CallShort a Call Short Stock & Short a PutShort Stock & Short a Put Long a PutLong a Put Short Stock & Long a Short Stock & Long a
CallCall Short a PutShort a Put Long Stock & Short a CallLong Stock & Short a Call
Synthetic Call: Long stock, sell a bond, Synthetic Call: Long stock, sell a bond, and buy a put. Exercise price = FV of and buy a put. Exercise price = FV of bond.bond.
Synthetic Put: Short stock, long call.Synthetic Put: Short stock, long call.
2727
Convertible SecuritiesConvertible Securities
Convertible BondsConvertible Bonds Convertible Preferred StocksConvertible Preferred Stocks Concepts the sameConcepts the same
2828
Conversion RatioConversion Ratio
Conversion Ratio = Par / Conversion Ratio = Par / Conversion PriceConversion Price
Conversion Price defined in Conversion Price defined in indentureindenture
Conversion ratio (or exchange Conversion ratio (or exchange ratio) = # of shares of common ratio) = # of shares of common stock received upon conversionstock received upon conversion
2929
Conversion Value & PremiumConversion Value & Premium
Conversion Value = Conversion Value = Conversion Ratio x Price of Conversion Ratio x Price of Common StockCommon Stock
Conversion Premium = Conversion Premium = Market Price of Bond – Conversion Market Price of Bond – Conversion ValueValue
% Conversion Premium = % Conversion Premium = Conversion Premium / Conversion Conversion Premium / Conversion ValueValue
3030
Value of Bond asDebt and as Stock
Value of ComparableNonconvertible Bond(Straight-Debt Value)
Price of Stock
Conversion Value
Bond Market Value
ConversionPremium
Conversion ValuesConversion Values
3131
Convertibles Always CallableConvertibles Always Callable
Allows company to force Allows company to force conversionconversion
Investor must convert or saleInvestor must convert or sale After call date, no longer accrues After call date, no longer accrues
interest or is convertibleinterest or is convertible
3232
Rates of Return on Rates of Return on ConvertiblesConvertibles
Historically:Historically:– Better than non-convertiblesBetter than non-convertibles– Worse direct ownership of equityWorse direct ownership of equity
Less risky than equity, riskier than Less risky than equity, riskier than straight debtstraight debt