Butterfly--蝴蝶交易
Butterfly - An order to simultaneously purchase an option with one strike price, purchase an option with a second strike price, and sell two options with a third strike price that is midway between the prices of the first two options. The ratio for a butterfly is always 1 x 2 x 1.
For example: Buy 10 March02 95 calls, Sell 20 March02 100 calls, Buy 10 March02 105 calls.