NO.PZ2020021203000114
问题如下：
What is the payoff from a portfolio consisting of a long position in both a floating lookback call and a floating lookback put?
解释：
A floating lookback call provides a payoff of ST - Smin and a floating lookback put provides a payoff of Smax - ST. The payoff from the portfolio is therefore the excess of the maximum asset price over the minimum asset price ( ST - Smin + Smax - ST = Smax - Smin).
我记得之前课上说 lookback call，如果ST越高，多头越赚钱，所以payoff 为Smax-K，对于put，如果ST越低，多头越赚钱，所以payoff为K-Smin。感觉和题目给的解释是反的，是我记错了吗？烦请老师解答。
