Steve wants to buy Amy's house 6 months in the future. However, house prices have been volatile lately; the value of Amy's house in 6 months is equal to its current market value scaled by a constant , where . Amy offers to sell the following contract: Steve receives the right but not the obligation to, in 6 months, purchase Amy's house at its current market value instead of its value then. Amy is willing to negotiate the price of the contract. What is the fair price for Amy's contract as a proportion of her home's current market value?