Topic 8 Portfolio Insurance & Other Advanced Derivatives Strategies Several Routes to Insured Portfolios • • • • Put options on the index Synthetic put using dynamic hedging Index futures using dynamic hedging Break forward contract 1 Put options on the index (Prob 1) • Today, a market index is at 1224.36 • You manage a portfolio that duplicates the index and is worth 21,000 times the index • 1210 puts on the index future, expiring in 90 days, have premium of $32.70 • You plan to sell some of the stock in order to fund the purchase of puts Put options on the index (Prob 1) • How many “shares” will you have in the revised portfolio, and how many puts? NS + NP = 21,000(1224.36) N(1224.36) + N(32.70) = 21000(1224.36) N(1224.36+ 32.70) = 21000(1224.36) N(1257.06) = 25,711,560 N = 20,453.73 • What is the value of the revised stock portfolio combined with this insurance? NS + NP = N(1224.36) + N(32.70) = 1257.06 * 20,453.73 = $25,711,560 2 What is the result of this strategy? • If puts expire worthless, you will have less stock and no more protection • If index stays above the breakeven point, you would still have reduced portfolio value with no more protection Breakeven: 1210 – 32.70 = 1177.30 • If index falls below the breakeven, you would be thankful for the protection 3 Further Practice (problem 2) • Suppose the index falls to 1201.25 at expiration Ø Value of the insured portfolio = (1201.25 * 20,453.73) + [(1210 – 1201.25) * 20,453.73] Ø Value of the insured portfolio = 1210 * 20,453.73 = $24,749,000 Ø This is the minimum value of the insured portfolio, no matter how far the value of equity might drop Ø Without portfolio insurance, value of uninsured portfolio would have been $1201.25 * 21000 = $25,226,250 Ø Breakeven be 24,749,000/21000 = 1177.52 Further Practice (problem 3) • Suppose the index rises to 1234.36 at expiration Ø Put expires worthless. Value of the insured portfolio = 1234.36 * 20,453.73 = $25,247,266 Ø Without portfolio insurance, value of uninsured portfolio would have been $ 1234.36 * 21000 = $25,921,560 Ø Cost of insurance: $25,921,560 – $25,247,266 = $674,294 (about 2.6% of the original portfolio value) Ø Upside capture is 100% – 2.6% = 97.4% 4 Basic Premise of Synthetic Options • We know that C(S,X,t) = S – B(X,t) + P(S,X,t) • We assume that for a very short time C(S,X,t) = ∂1S – ∂2B(X,t) 5 Here’s a Picture of ∂1 Call Call ∆C/∆S C2 C1 Stock B B(X,t) (X,t) S1 Stock S2 Here’s a Picture of ∂2 Call Call ∆C/∆X C1 C2 BB(X,t) (X1,t) S B (X2,t) Stock Stock 6 Important Relationships • ∂1 and ∂2 are always less than 1 • ∂2 is always less than ∂1 • Exact values can be estimated using the Black-Scholes OPM • Proportions must be continuously adjusted Example • Suppose ∂1 = 0.7 ∂2 = 0.6 S = $50 B(X,t) = $46 • Then C(S,X,t) = (. 7*50) – (.6*46) = $7.40 • Then, sell 100-option contract (receive $740) Ø Sell 60 bonds (receive another $2760, making total $3500) Ø Buy 70 shares stock (pay $3500) Ø Zero net investment • After a moment Ø S = $50.125 Ø B(X,t) = $46.10 Ø C(S,X,t)=7.4275 • Close position, net zero 7 Example • Now, suppose calls selling on CBOE for $7.75 per share Ø Sell 100-share call contract for $775 Ø Create synthetic for $740 Ø Pocket profit of $35 • How will adjustment process work? Basic Premise for Portfolio Insurance • From put-call parity, we know that C(S,X,t) + B(X,t) = S + P(S,X,t) • Then let’s make a simple rearrangement S + P(S,X,t) = C(S,X,t) + B(X,t) • We assume that for a very short time C(S,X,t) = ∂1S – ∂2B(X,t) • Then for a short time S + P(S,X,t) = B(X,t) + ∂C(S,X,t) 1S – ∂2B(X,t) S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) 8 How does insurance work? Call Call S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) ∂ close to 1 ∂ declines Less in stock More in bonds B (X,t) B(X,t) Stock S2 Stock S1 How does insurance work? Call Call S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) ∂ closer to 1 Sell bonds Buy more stock ∂ less than 1 B (X,t) B(X,t) Stock S1 Stock S2 9 How might this process lead to runup? Call Call S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) ∂ closer to 1 Sell bonds Buy more stock ∂ less than 1 B (X,t) B(X,t) Stock S1 Stock S2 How might this process lead to meltdown? Call Call S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) ∂ close to 1 ∂ declines Less in stock More in bonds B (X,t) B(X,t) Stock S2 Stock S1 10 Practice (Problem 4) • Today, a market index is at 1224.36 • You manage a portfolio that duplicates the index and is worth 21,000 times the index • You want to maintain a protection window that maintains a constant 90-day time horizon • Volatility of the index is 17.5% • Continuously compounded T-Bill rate is 5% • Dividend yield on the index now is 3% per year with continuous compounding Practice (Problem 4) S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) • We can be somewhat more precise in finding the new proportions to hold of equity and bonds in order to mimic equity plus synthetic puts. First, let’s calculate the new N: Nnew = Nold (S/(S + Put) Nnew = Nold S ∂1S + (1– ∂2)B(X,t) 11 Practice (Problem 4) New N = Nnew = Nold S ∂1S + (1– ∂2)B(X,t) 21000 * 1224.36 (.5933 * 1224.36) + (1– .5592)*1204.05 Nnew = 20,453.71 Practice (Problem 4) Number of Shares = ∂1 * 20453.71 Number of Shares = .5933 * 20453.71 Number of Shares = 12,134.58 12 Practice (Problem 4) S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) Number of Bonds = Nnew * (1– ∂2) Number of Bonds = 20453.71*(1– .5592) Number of Bonds = 9014.98 Basic Premise of Futures Hedge • We want to create a portfolio of stock and futures that responds the same way to changes in stock price as a portfolio of stock & put • From put-call parity, we know that C(S,X,t) + B(X,t) = S + P(S,X,t) • We assume that for a very short time C(S,X,t) = ∂1S – ∂2B(X,t) • Then for a short time S + P(S,X,t) = B(X,t) + ∂C(S,X,t) 1S – ∂2B(X,t) S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) 13 Calculating the Futures Hedge • Goal: ∂V/ ∂S = Delta for insured portfolio = Nnew ∂C/ ∂S • ∂V/ ∂S = Nold + Nf (∂f / ∂S) • We know that ∂f / ∂S = e(r-d)t This is because f0(t) = S0 e(r-d)t • So, Nold + Nf e(r-d)t = Nnew ∂C/ ∂S S + P(S,X,t) = ∂1S + (1 – ∂2 ) B(X,t) Calculating the Futures Hedge • Nold + Nf e(r-d)t = Nnew ∂C/ ∂S • Nf = Nold {[(Nnew / Nold)∂C/ ∂S]–1} e–(r–d)t • We remember that Nnew = Nold [S/(S+P)] • So: Nf = Nold {[∂C/ ∂S S/(S+P)]–1} e–(r–d)t • Number of contracts = Nf /multiplier 14 Practice (Problems 5&6) • Nf = Nold {[∂C/ ∂S S/(S+P)]–1} e–(r–d)t • Problem 5: ∂C/ ∂S S/(S+P) = .5933 * 1224.36/(1224.36+32.70) = .5778 • Then in problem 6: Nf = 21000 * [ (.5778 – 1) e–(.05–.03)(90/365)] Nf = –8822.58 • Number of contracts = –8822.58 /250 = –35.29 Break Forward Contract • This is a variation on an Equity Forward • Value at origination is zero • It is like a pay-later call, in which the buyer pays nothing at time of purchase, but pays the future value of the call premium at expiration Ø If the call expires in-the-money, the deferred premium is deducted from the proceeds of exercise (this may still be negative if the underlying falls below the breakeven) Ø If the call expires out-of-the-money, the buyer must pay the entire deferred premium • The exercise price is the equilibrium forward price Ø X = S0e(r-d)t 15 Break Forward Contract • Payoff at expiration depends on the value of the underlying at expiration Ø If ST > f0(T) the payoff is ST – f0(T) – C(S,X,t)ert Ø If ST ≤ f0(T) the payment is –C(S,X,t)ert Ø Payoff is positive if ST ≥ f0(T) + C(S,X,t)ert • Break forwards could be substituted for calls in a call-bond portfolio insurance strategy X = strike price of the call = f0(T) f0(T) is the equilibrium forward price f0(T) = S0e(r-d)t 16 Break Forward Contract • The present value of the exercise price is S0, so the call starts out exactly at the money • Put-call parity shows another analogy that is helpful in understanding a break forward contract C(S,X,T) +S = S + P(S,X,T) C(S,X,T) – P(S,X,T) = 0 But, there is no short put in the break forward, so you must pay for the option • The “loan” implicit in the break forward is the price of the call, for which payment is deferred until expiration X = strike price of the call = f0(T) f0(T) is the equilibrium forward price f0(T) = S0e(r-d)t Further Practice (problems 8-10) • Strike price = $43.75 e(.0375*(270/365)) = $44.98 • The puts and calls are each worth $2.70 per share • Face value of the “loan” would be $2.70 e(.0375*(270/365)) = $2.7759 per share • Stock price rises to $46.50 at expiration Ø Payoff per share = $46.50 – $44.98 – $2.78 = –$1.26 • Stock price falls to $42.50 at expiration Ø Option expires out of the money. Ø Payoff per share = – $2.78 • Breakeven point is $44.98 + $2.78 = $47.76 17 Exotic Options • Digital Options • Chooser Options • Path-Dependent Options Ø Asian Options Ø Lookback Options Ø Barrier Options 18 Digital Options Break a Call in Two • Digital options, sometimes called binary options, are of two types: Ø Asset-or-nothing options • pay the holder the asset if the option expires in the money and nothing otherwise. Ø Cash-or-nothing options • pay the holder a fixed amount of cash (usually $1) if the option expires in the money and nothing otherwise Decomposition of a European Call • A balanced portfolio of long asset-ornothing options and short cash-ornothing options is equivalent to a European Call Ø Oaon = S0 N(d1) Ø Ocon = e–rt N(d2) • So, C(S,X,t) = Oaon – XOcon 19 Practice • For practice, see problems 11 through 13 on Set 7 Chooser Options • Also called as-you-like-it options • Enable investor to decide whether the option will be a call or a put Ø at a specific time after purchasing the option Ø but before expiration 20 Chooser Options • The chooser option is identical to Ø an ordinary call expiring at T with exercise price X plus Ø an ordinary put expiring at t with exercise price Xe-r(T-t) • How does this compare with a straddle? Ø Different time to expiry Ø Different exercise price Decision must be made at time t < T Practice • For practice, see problem 14 on Set 7 21 Contingent-pay Option • Like a pay-later option Ø Premium paid at expiration • Except: Ø Premium paid only if the option expires inthe-money Contingent-pay Option • It is a combination of a standard option and Ccp cash-or-nothing calls • The value must be zero today so: Ce(S,X,t) – Ccpe–rt N(d2) = 0 Ccp = Ce(S,X,t) / e–rt N(d2) Ccp = Calle / Ocon 22 Practice • For practice, see problem 15 on Set 7 Path-Dependent Options • Payoff is determined by Ø sequence of prices followed by the asset Ø not just by the asset’s price at expiration • 1st example: Asian Option 23 Path-Dependent Options • Lookback Option Ø Also called a no-regrets option Ø Permits purchase of the asset at its lowest price during the option’s life or Ø Sale of the asset at its highest price during the option’s life Path-Dependent Options • Four different types of Lookback Options Ø lookback call: exercise price = minimum price during option’s life Ø lookback put: exercise price = maximum price during option’s life Ø fixed-strike lookback call: payoff based on maximum price during option’s life (instead of final price) • compared to fixed strike Ø fixed-strike lookback put: payoff based on minimum price during option’s life (instead of final price) • compared to fixed strike 24 Path-Dependent Options • Barrier Options: Ø Terminate early if the asset price hits a certain level, called the barrier • Called knock-out options (or simply out-options) Ø Activate only if the asset price hits the barrier • called knock-in options (or simply in-options) • If the barrier is above the current price Ø called an up-option • If the barrier is below the current price Ø called a down-option • Normally cheaper than ordinary options because fewer outcomes provide pay offs Compound Option: An Option on an Option • Four basic types Ø Call on a call Ø Put on a call Ø Call on a put Ø Put on a put • Two strikes; two expirations • Two Premia Ø 1st paid up front Ø 2nd paid if exercised • Often used in mkts where there is doubt about volatility of ultimate underlying (such as currencies) 25 Other Exotic Options • • • • • • • exchange options multi-asset options min-max options (rainbow options) outperformance options forward-start and tandem options deferred strike options shout, cliquet and lock-in options 26