我把原帖copy paste 到这里吧。
- ratio put spread: Used when stock sold off towards bottom of a wave, the purpose is to buy more shares at lower price
- put spread: Used when stock is at high point of a wave, the purpose is to profit from the potential decline
- call spread: Used when stock is near the bottom of a wave, the purpose is to profit from the potential bounce
- ratio call spread: Used when stock is near the high of the wave, the purpose is to lower the average cost of the main holding when stock drops , plus willing to sell with better profit if it keeps going up
