huha2022-11-21 19:52:01

老师好，原版书有一句话描述calendar spread说‘’In sum, a big move in the underlying market or a decrease in implied volatility will help a short calendar spread, whereas a stable market or an increase in implied volatility will help a long calendar spread. Thus, calendar spreads are sensitive to movement of the underlying but also sensitive to changes in implied volatility.‘’short calender不是long short-term call+short long-term call么？那么long call不是long volatility么？这里为啥说a decrease in implied volatility will help a short calendar spread呢？