An option order whereby a trader can simultaneously buy and sell a number of different options that usually could only be initiated by placing separate orders. This type of order is mainly used in constructing multi-legged strategies such as combinations, straddles, strangles, ratio spreads, butterfly spreads, etc. In other words, it allows the average option trader to establish advanced options strategies that are made up of many options by placing one order and only paying one commission.

For example, one multi-leg order can be placed to buy one call option with a strike price of $50 and one put option with a strike price of $50 (straddle strategy). Likewise, it can be used to simultaneously buy one call option and one put option of the same underlying, but with different strike price, different expiration dates, or both different strike prices and different expiration dates (a long combination).