11 Consider the ternary model for the underlying of $1.4. How many equivalent martingale measures are there? If there are two different martingale measures, do they give the same price for a claim? Are there arbitrage opportunities? a 1.5 A CHARACTERISATION OF NO ARBITRAGE 9 *+ $x = (S, 3000) Figure 1.3 If the stock price takes three possible values at time T, then at any point where the seller of the option has no risk of making a loss, she has a strictly positive chance of making a profit. 11 Consider the ternary model for the underlying of $1.4. How many equivalent martingale measures are there? If there are two different martingale measures, do they give the same price for a claim? Are there arbitrage opportunities? a 1.5 A CHARACTERISATION OF NO ARBITRAGE 9 *+ $x = (S, 3000) Figure 1.3 If the stock price takes three possible values at time T, then at any point where the seller of the option has no risk of making a loss, she has a strictly positive chance of making a profit