这边要构建一个cashless collar，答案是说用long stock + long put at X(low)+short call at X(high)。
画了图，这样一个头寸类似bull spread。
我想问的是为什么long stock + long put at X(high) + short call at X(low)就不行？画了下图，是个类似bear spread的图，也看起来是个collar啊。求解答。
还是说collar的定义就是一定要long stock + long put at X(low)+short call at X(high)?
