An OSO (Order Sends Order) order consists of a primary order that will send one or more secondary orders when the primary order is filled.
For example, there is an OSO order consisting of three orders. The primary order 1) is a limit order to buy 1000 shares of a symbol, and attached to it are two other orders: 1) a limit order to buy 500 shares of another symbol in the same industry and 2) an stop order for 1000 share of the primary symbol at a price .25 below the limit price for that order. When the primary order is filled, the two additional OSO orders are sent, one that buys additional shares of a related symbol and another that sets a stop loss for the primary symbol.
