Derivatives Workshop
Actuarial Society October 30, 2007
Agenda
Intro to Derivatives Buying/Short-selling Forwards Options Swaps
What are Derivatives?
A financial instrument that has a value determined by price of something else A contract whose value depends on what something else is worth
Futures Swaps
– Options – Insurance
Why use Derivatives?
Risk management
Hedging
Speculation Reduced transaction costs Regulatory arbitrage
Buying an Asset - Long Position
Offer price (ask price) Bid price Bid-ask spread Commission (flat or percentage)
Example
Bid price = $50; Ask price = $50.25 Commission = $1/transaction How much does it cost to buy 100 shares, then immediately sell it? Cost = $50.25*100 - $50*100 + $2 = $27
Short-Selling
Borrow now Sell now Buy later (covering the short position) Return later Lease rate of asset – payments that must be made before repaying asset
Why Short-sell?
Speculation Financing Hedging
Example
Stock price now = $50 Stock price one year from now = $49.50 Commission = $1/transaction How much can you make short selling 100 shares? Profit = $50*100-$49.50*100-$2 = $48
Forward Contracts
Sets terms now for the buying or selling of an asset at specified time in future
Specifies quantity and type of asset Sets price to be paid (forward price) Obligates seller to sell and buyer to buy
Settles on expiration date
Forward Contracts
Forward price -- price to be paid Spot price -- market price now Underlying asset -- asset on which contract is based Buyer = long; Seller = short
Long position makes money when price Short position makes money when price
Payoffs in Forward Contract
Payoff to long forward (buyer) = Spot price at expiration - forward price
Agreed to buy at fixed (forward) price
Payoff to short forward (seller) = Forward price - spot price at expiration
Agreed to sell at fixed price
Call Options
Contract where buyer has the right but no obligation to buy
Seller is obligated to sell, if the buyer chooses to exercise the option
Since seller cannot make money, buyer must pay premium for option
Forwards have no premium
Call Options
Strike price - amount buyer pays for the asset Exercise - act of paying strike price to receive the asset Expiration - when option must be exercised, or become worthless European style - only exercise on x-date Bermudan style - during specified periods American style - entire life of option
Payoff of Call Option - Long
Buyer is not obligated to exercise -- will only do so if payoff is greater than 0 Purchased call payoff = max[0, spot price at x-date - strike price]
Must pay premium to seller
Profit = payoff - future value of premium
Payoff of Call Option - Short
Opposite to payoff/profit of buyer Written call payoff = -max[0, spot price at x-date - strike price]
Only profits from premium
Profit = - payoff + future value of premium
Put Options
Contract where seller has the right but no obligation to sell
Buyer is obligated to buy, if the seller chooses to exercise the option
Since buyer cannot make money, seller must pay premium for option Seller of asset = buyer of put option
Insurance Strategies
Buying put option – floor (min sale price) Buying call option – cap (max price) Covered writing – writing option with corresponding long position Naked writing – no position in asset
Covered writing
Covered call
Same as selling a put Asset whose price is unlikely to change
Covered put
Same as writing a call
Synthetic Forwards
BUY CALL & SELL PUT
FORWARD CONTRACT
Must pay net option premium Pay strike price
Zero premium Pay forward price
Put-Call Parity
No arbitrage Net cost of index must be same whether through options or forward contract
Call (K,T) – Put(K,T) = PV(F0,T – K)
Spreads – Only calls/only puts
Bull: buy call, sell call with higher strike price Bear: buy higher strike price, sell lower Box: synthetic long forward and synthetic short forward at different prices Ratio spread: buy m calls and sell n calls at different strike prices
Can have zero premium (only pay if you need the insurance)
Collars
Buy put, sell call with higher strike Collar width – difference between call and put strikes Similar to short forward contract
Straddles
Buying call and put with same strike price Profits from volatility in both directions Premiums are costly (paying twice)
Strangle
Same as straddle, but buy out-of-the-money options Premiums will be lower Stock price needs to be more volatile in order to make profit
Written Straddle
Sell call and put with same strike price Profits when volatility is low Potential unlimited loss from stock price changes in either direction
Butterfly Spreads
Insures against losses from a written straddle Out-of-the-money put provides insurance on the downside Out-of-the-money call provides insurance on the upside
Swaps
Contract for exchange of payments over time Forward is single-payment swap Multiple forwards, but as single transaction