Derivatives: Option Markets and Contracts Flashcards
Delta Hedging
Number of shares in contract = Investment / Delta
Gamma is Greatest for…
At the money options
Put-Call Parity
Po = Co - So + x/e^(r)(t)
- t should be in decimal form (90 days = .25)*
- this formula assumes continuous compounding*
Put-Call Parity for Futures and Forwards
P0 = Co + [(X - F(0,T) / 1+r^t]
- F(0,T) = value of future now that expires in time T*
- The numerator could be negative*
Value of Call Option for one period (Binomial Model) including probability calculation
Step 1: Calculate max gain for up and down move
Step 2: prob = (1 + Rf% - d) / u - d
Step 3: Co = [prob(call+) + 1-prob(call-)] / (1 + Rf%)
- d = 1 - the likely decline in value in percentage terms*
- u = 1+ the likely rise in value in percentage terms*
- call+ = The maximum value of the call assuming the positive forecast comes true at expiration*
Value of Call (binomial model) - Two Periods
Step 1: Calculate max gain for up, down, and up/down-down/up moves - up and down move must be squared
Step 2: prob = (1 + Rf% - d⁻⁻) / u⁺⁺ - d⁻⁻
Step 3a: C⁺⁺ = [prob(call⁺⁺) + 1-prob(call⁺⁻)] / (1 + Rf%)
Step 3b: C⁻⁻ = [prob(call⁺⁻) + 1-prob(call⁻⁻)] / (1 + Rf%)
Step 4: C = [prob(C⁺⁺) + 1-prob(C⁻⁻)] / (1 + Rf%)
- d = 1 - the down move (or 1/1+upmove if no down move given)
- u = 1+ the up move
- call+ = The maximum value of the call assuming the positive forecast comes true at expiration
Assumptions about Black Scholes Merton (BSM) Formula
- Volatility of the return on the underlying stock is known and constant
- Stock prices are lognormally distributed
- Continuous Rf% is known and constant