Class President Says I Rigged Stocks; Seeing Comments, I Went Berserk

I won the intercollegiate stock-trading contest, but when I got back to my dorm, the class president stopped me at the door. "You know better than I do how you got that trophy." "Give up your graduate-recommendation slot, and I'll keep your secret for you." Seeing the confusion on my face, he sneered. "If I didn't know the truth, I might actually have fallen for that innocent little act of yours."