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Options Markets: Introduction
Wong Wei Kang
Do not distribute without permission
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Outline • Call & Put Options • American vs. European Options • Option versus Stock Investments • Protective Put • The Put-Call Parity Theorem
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Options • Derivative securities or derivatives are securities that
get their value from the price of other securities • Also called contingent claims because their payoffs
are contingent on the prices of other securities • Powerful tools for hedging or speculation. • Hedge – To reduce risk by holding contracts or securities whose
payoffs are negatively correlated with some risk exposure
• Speculate – When investors use contracts or securities to place a bet on
the direction in which they believe the market is likely to move
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Options • Options are traded both on organized exchanges
and OTC • Chicago Board Options Exchange (CBOE) began
listing call options in 1973 – Standardization of the terms of listed option contracts
increases market depth and lowers trading costs
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Call Option • A call option gives its holder the right to buy
an asset: – At the exercise price (X) or strike price (K) – On or before the expiration date
• It’s a right. Not an obligation. So exercise the option only if it is profitable to do so.
• Exercise the option to buy the underlying asset if market value > strike price
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Put Option • A put option gives its holder the right to sell an
asset: – At the exercise price (X) or strike price (K) – On or before the expiration date
• It’s a right. Not an obligation. So exercise the option only if it is profitable to do so.
• Exercise the option to sell the underlying asset if market value < strike price.
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The Option Contract • The purchase price of the option is called the
premium. • Option Writer: the seller of an option contract • Sellers (writers) of options receive premium
income. • If the option buyer (holder) exercises the
option, the option writer must make (for call) or take (for put) delivery of the underlying asset.
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Example 20.1 Profit and Loss on a Call • A January 2010 expiration call on IBM with an exercise price of
$130 was selling on December 2, 2009, for $2.18. – The option expires on the third Friday of the month, or January
15, 2010. • If IBM remains below $130, the call will expire worthless. • Suppose IBM sells for $132 on the expiration date.
– Option value = stock price – exercise price $132 – $130= $2
– Profit = Final value – Original investment $2.00 – $2.18 = –$0.18
– Option will be exercised to offset loss of premium. • Call will not be strictly profitable unless IBM’s price exceeds
$132.18 (strike + premium) by expiration. 8
Example 20.2 Profit and Loss on a Put
• Consider a February 2013 put on IBM with an exercise price of $195, selling on January 18, for $5.00. – Option holder can sell a share of IBM for $195 at any time
until February 15.
• If IBM goes above $195, the put is worthless. Might as well sell at the higher market price.
• Suppose IBM’s price at expiration is $188. – Value at expiration = exercise price – stock price =$195 -
$188 = $7
– Investor’s profit = $7.00 - $5.00 = $2.00
• Holding period return = 40% over 28 days! 9
Market and Exercise Price Relationships
In the Money - exercise of the option produces a positive cash flow Call: exercise price < asset price Put: exercise price > asset price
Out of the Money - exercise of the option would not be
profitable Call: asset price < exercise price. Put: asset price > exercise price.
At the Money - exercise price and asset price are equal
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Market and Exercise Price Relationships
• Deep In-the-money – Describes an option that is in-the-money and for
which the strike price and the stock price are very far apart
• Deep Out-of-the-money – Describes an option that is out-of–the-money and
for which the strike price and the stock price are very far apart
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Figure 20.1 Stock Options on IBM closing prices Open Interest = Number of Outstanding Contracts
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American vs. European Options American - the option can be exercised at any time before expiration or maturity European - the option can only be exercised on the expiration or maturity date
• In the U.S., most options are American style, except for currency and stock index options.
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Stock Split and Dividend Payout • To account for stock split, the exercise price is reduced by
a factor of the split, and the number of options held is increased by that factor.
• A similar adjustment is made for stock dividends of more than 10%.
• Cash dividends do not affect the terms of an option contract. – Call option values are lower for high-dividend payout policies
because they slow the stock price increase – Vice versa for put option
• Anticipated dividend payments are factored into the option price.
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Different Types of Options • Stock Options • Index Options – Options based on a stock market index such as the S&P
500 or NASDAQ100 • Futures Options – give holders the right to buy or sell a specified futures
contract • Foreign Currency Options – offer the right to buy or sell a quantity of one currency for a
specified amount of another currency • Interest Rate Options – Traded on Treasury notes and bonds, etc.
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Calls: Payoffs and Profits at Expiration
Payoff to Call Holder (ST - X) if ST >X 0 if ST < X
Profit to Call Holder Payoff – Premium
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Notation Stock Price = ST Exercise Price = X
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Figure 20.2 Payoff and Profit to Call Option at Expiration Exercise Price = $100; Premium = $14
Calls: Payoffs and Profits at Expiration
Payoff to Call Writer
- (ST - X) if ST >X 0 if ST < X
Profit to Call Writer
Payoff + Premium
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Figure 20.3 Payoff and Profit to Call Writers at Expiration Exercise Price = $100; Premium = $14
Puts: Payoffs and Profits at Expiration
Payoffs to Put Holder 0 if ST > X (X - ST) if ST < X
Profit to Put Holder
Payoff - Premium
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Figure 20.4 Payoff and Profit to Put Option at Expiration Exercise Price = $100
Puts: Payoffs and Profits at Expiration
Payoffs to Put Writer 0 if ST > X - (X - ST) if ST < X
Profits to Put Writer
Payoff + Premium
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Summary: Holder vs. Writer and Call vs. Put
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Bullish vs. Bearish Strategy
• Bullish Strategy – Buying Calls – Writing Puts – Profits when stock prices increase
• Bearish Strategy – Buying Puts – Writing Calls – Profits when stock prices fall
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Option vs. Stock Investments
• Could a call option strategy be preferable to a direct stock purchase?
• Suppose you think a stock, currently selling for $100, will appreciate.
• A 6-month call costs $10. • You have $10,000 to invest.
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Option vs. Stock Investments • Strategy A: Invest entirely in stock. Buy 100 shares,
each selling for $100.
• Strategy B: Invest entirely in at-the-money call options. Buy 1,000 calls, each selling for $10.
• Strategy C: Purchase 100 call options for $1,000. Invest your remaining $9,000 in 6-month T-bills, to earn 3% interest for 6 months. The bills will be worth $9,270 at expiration.
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Option vs. Stock Investment
Investment Strategy Investment Equity only Buy stock @$100 100 shares $10,000 Options only Buy calls @$10 1000 calls $10,000 Call plus Bills Buy calls @$10 100 calls $1,000
Buy T-bills @ 3% $9,000 Yield
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Strategy Payoffs
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Figure 20.5 Rate of Return to Three Strategies
Strategy Conclusions • Figure 20.5 shows that the all-option portfolio, B,
responds more than proportionately to changes in stock value; it is levered. – Options can be used by speculators as effectively leveraged
stock positions
• Portfolio C, T-bills plus calls, shows the insurance value of options. – C’s T-bill position cannot be worth less than $9270. – Some return potential is sacrificed to limit downside risk. – The absolute limitation on downside risk is a novel and
attractive feature of this strategy 30
Protective Put • Protective Put = Stock + Put • Invest in stock and buy a put option on the stock • Puts can be used as insurance against stock price
declines. • Protective puts lock in a minimum portfolio value. • The cost of the insurance is the put premium. • Options can be used for risk management, not just
for speculation.
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Table 20.1 Value of a Protective Put Position at Expiration
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Figure 20.6 Value of a Protective Put
Position at Expiration
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Figure 20.7 Protective Put vs. Stock Investment (at-the-money option)
Put-Call Parity • A protective put portfolio (stock-plus-put) provides a
payoff with a guaranteed minimum value, but with unlimited upside potential – Table 20.1 – Figure 20.6
• But a call-plus-bills portfolio can also provide similar payoff – Buy a call option and buy zero-coupon Treasury bills with
face value equal to the exercise price X of the call and with maturity date equal to the expiration date of the option
– Next Table
– Figure 20.5
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Value of a Call-plus-Bills Portfolio at Expiration
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The Put-Call Parity Theorem
• Since both portfolios provide the same exact payoffs, the call-plus-bond portfolio (on left) must cost the same as the stock-plus-put portfolio (on right):
0(1 )Tf
XC S Pr
+ = ++
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Put-Call Parity Disequilibrium Example
Stock Price = 110 Call Price = 17 Put Price = 5 Risk Free = 5% Maturity = 1 yr X = 105
117 > 115 Since the protective put is less expensive, acquire the low cost alternative and sell the high cost alternative
0(1 )Tf
XC S Pr
+ = ++
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Table 20.5 Payoff to Arbitrage Strategy
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The Put-Call Parity Theorem
• Extension for European call options on dividend-paying stocks
S0 + P = C + PV(X) + PV(dividends)
where PV(dividends) = Present value of the dividends that will be paid by the stock during the life of the option
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