Learning Module 10 Valuing a Derivative Using a One-Period Binomial Model
45 questions available
Key Points
- Underlying moves only to two possible prices: S1_u or S1_d
- Hedge ratio h = (option up payoff - option down payoff) / (S1_u - S1_d)
- Hedged portfolio payoff is risk-free and must earn risk-free rate
- Option price from replication: discount the certain payoff
- Model depends on Ru and Rd (volatility) and risk-free rate, not real-world probabilities
Key Points
- Risk-neutral probability pi = (1 + r - Rd) / (Ru - Rd)
- Option price = discounted risk-neutral expected payoff
- Real-world probabilities do not affect no-arbitrage price
- Higher Ru - Rd (volatility) increases option prices
- Risk-free rate shifts influence put and call differently through discounting and pi
Key Points
- Numeric examples show hedge ratio and option price computation
- Put prices derived from call prices via put-call parity remain consistent with binomial valuation
- Arbitrage arises if market option prices deviate from no-arbitrage values
- Method extends to multi-period binomial trees
- Firm-value and other conceptual applications connect option views to balance-sheet claims
Questions
In a one-period binomial model the underlying price S0 = 50. After the period it will be either S1_u = 65 or S1_d = 40. A European call with strike X = 55 expires at period end. If the risk-free rate for the period is 2 percent, what is the hedge ratio h for a short call position replicated by buying h units of the underlying?
View answer and explanationA stock S0 = 80 will be either 110 (up) or 60 (down) next period. A call with X = 100 has payoffs 10 and 0 in the states. If r = 5 percent, what is the risk-neutral probability pi of an up move?
View answer and explanationTrue or false: In the one-period binomial model, the actual real-world probability q of an up move affects the no-arbitrage option price.
View answer and explanationStock S0 = 100 is expected to go to either 130 or 70. Consider a put with X = 90 and r = 0. What is the put payoff vector (p1_u, p1_d)?
View answer and explanationA put's payoffs are (0, 20) as in Question 5. With pi = 0.58333 and r = 5 percent, what is the put price p0?
View answer and explanationWhich of the following statements best describes why put and call prices derived from the one-period binomial model do not require investors' risk preferences?
View answer and explanationStock S0 = 16 moves to either 20 or 12. If r = 5 percent, what is the risk-neutral probability pi?
View answer and explanationIn a one-period model, increasing the spread between Ru and Rd while keeping S0 and r fixed will generally:
View answer and explanationYou sell a call and buy h units of the underlying to form a risk-free portfolio. If V1 is the common payoff in both states and r is the period rate, which equation gives c0 (call price)?
View answer and explanationIf a call option is overpriced relative to the binomial no-arbitrage price, an arbitrageur should:
View answer and explanationWhich of the following is a correct expression of the hedge ratio for any derivative whose value at expiry depends only on the underlying price in the two states?
View answer and explanationGiven S0 = 120, S1_u = 150, S1_d = 90, X = 110, r = 4 percent. A call's payoffs are (40, 0). Compute c0 using risk-neutral pricing.
View answer and explanationIf the risk-free rate increases while Ru and Rd remain unchanged, which of the following is typically true for European calls and puts (other things equal)?
View answer and explanationA derivative has payoffs c1_u = 30 and c1_d = 5. Under S1_u = 150 and S1_d = 100 and S0 = 120, what is the hedge ratio h?
View answer and explanationWhich of the following best explains why replication pricing yields the same option price as discounted risk-neutral expected payoff?
View answer and explanationIf a one-period binomial model gives h = 0.2 and S0 = 80 and the common payoff V1 = 12 with r = 5 percent, what is the call price c0?
View answer and explanationA European call in a one-period model has c1_u = 12 and c1_d = 0. If S1_u = 132, S1_d = 88 and S0 = 110, what is h?
View answer and explanationWhich factors determine the risk-neutral probability pi in a one-period binomial model?
View answer and explanationConsider S0 = 300, S1_u = 360, S1_d = 240, X = 320, r = 0. What is the call's up and down payoff vector (c1_u, c1_d)?
View answer and explanationIf the hedged portfolio yields V1 = 50 in both states and r = 10 percent, what is present value V0 used in replication pricing?
View answer and explanationA trader constructs a synthetic long underlying by combining a long call, short put (same X and T) and lending PV(X). Which parity principle justifies this?
View answer and explanationIn a one-period binomial model, if S0 = 50, Ru = 1.4, Rd = 0.8, and r = 5 percent, what is Ru - Rd?
View answer and explanationWhich of the following is NOT required to compute the no-arbitrage price of a European option in a one-period binomial model?
View answer and explanationYou observe a call priced below its binomial no-arbitrage value. Arbitrage strategy to exploit this mispricing is to:
View answer and explanationA one-period call has c1_u = 8, c1_d = 1. Under S1_u = 120, S1_d = 80, S0 = 100, r = 2 percent. What is the hedge ratio h?
View answer and explanationWhich statement about multi-period extension of the one-period binomial model is correct?
View answer and explanationWhen forming a hedged portfolio by selling one call and buying h shares, the portfolio is risk-free because:
View answer and explanationIf a put is overpriced in the market relative to its binomial no-arbitrage price, an arbitrageur should:
View answer and explanationWhich of the following increases the risk-neutral probability pi for an up move, holding Ru and Rd constant?
View answer and explanationWhy does increasing Ru and decreasing Rd (wider up/down moves) raise both call and put prices?
View answer and explanationA protective put portfolio equals which of the following at inception according to put-call parity?
View answer and explanationIf S0 + p0 > c0 + PV(X) in the market, an arbitrageur should:
View answer and explanationA stock S0 = 295, forward price F0(T) = 300.84, r and T such that PV(X)=295. Which statement about a call and put with X = F0(T) is correct today?
View answer and explanationYou calculate a put price via binomial model as 6.20. Market put trades at 7.00. Which elementary arbitrage is suggested by the chapter?
View answer and explanationWhich statement about the hedge ratio h is correct as option goes deeper in-the-money (all else equal)?
View answer and explanationGiven S0 = 50, S1_u = 75, S1_d = 25, a call with X = 60 has payoffs (15, 0). If r = 0 and you short the call and buy h underlying to hedge, what is V1 (common payoff) you will obtain?
View answer and explanationIf option c0 equals 4.57 as earlier example and S0 = 80, h = 0.2, what is current value of hedged portfolio V0?
View answer and explanationA one-period model yields pi = 0.48. Option payoffs are c1_u = 10 and c1_d = 0. With r = 5 percent, what is c0?
View answer and explanationA stock pays no dividends. If you observe a call and put with same X and T, which parity holds that links calls, puts, underlying, and bond?
View answer and explanationA trader wants to replicate a sold call when exercise is certain at maturity. Which replication matches the sold-call payoff according to the chapter?
View answer and explanationYou price a call using replication and obtain c0 = 5.00. Using put-call parity with S0 = 50 and PV(X) = 45, what should the put p0 equal?
View answer and explanationIf an option's time-to-expiration shortens (T decreases) while other inputs unchanged, what is the typical effect on option time value?
View answer and explanationA bank observes a one-period call price computed as 6 by the binomial model but market call is 8. If frictionless trading is possible, net initial cash flow from arbitrage by following correct strategy?
View answer and explanationWhich of the following best describes why both put and call premiums increase when volatility rises (holding other inputs constant)?
View answer and explanationIn the one-period binomial model, which of the following reasons explains why the underlying's expected return mu does not affect option price?
View answer and explanation