Assume the effective 6-month interest rate is 2% and the S&R 6-month forward price is $1020. The premiums for S&R options with 6 months to expiration are as follows:

Strike Call Put

$950 $120.405 $51.777

1000 93.809 74.201

Construct payoff and profit diagrams for the purchase of a 950-strike S&R call and sale of a 1000-strike S&R call (call spread). Verify that you obtain exactly the same profit diagram for the purchase of a 950-strike S&R put and sale of a 1000-strike S&R put (put spread). What is the difference in the payoff diagrams for the call and put spreads? Why is there a difference?