A municipality required immediate funding so they issued a $500 000 bond paying a 4 percent semiannual coupon. When the yield was 3.5 percent compounded semi-annually, the bond had seven years left to maturity and an investor purchased it. However, three years later, the investor required money and sold the bond. If the yield at the time of the sale was 5 percent compounded semi-annually, how much did the investor gain or lose on this investment?