嗨,从没放弃的小努力你好:
当put option OTM时,代表的是S>X,payoff 如下图所示:

由于protective put是由long put+long bond+long forward组成,当put OTM时,payoff为0,到期末,bond会收到F0(T),forward 的payoff时ST- F0(T),而option payoff为0,总收益就是ST
----------------------------------------------虽然现在很辛苦,但努力过的感觉真的很好,加油!