Consider a one-period model for the price of a stock s

Question

Consider a one-period model for the price of a stock s: suppose Its time-0 value S₀ is known, and it is known that at T, its value is either S_u or S_d. Assume further that V is a derivative on S expiring at time T; suppose it’s time-0 value is l4. and that at time T, it has value U if the stock price is S_u or D if the stock price is S_d. Use the arbitrage theorem to prove that the risk-neutral probability is given by

And