There are about half a dozen different stop trigger methods. They are documented (C#) under?IBApi.TriggerMethod enumeration and specified using Order::TriggerMethod property, as well as when manually submitting an order in TWS. Rules governing these methods are sometimes somewhat intricate so pay attention to what documentation say, and I suggest you should ideally?look at documentations for both API and TWS since IBKR docs can be somewhat sparse. Trigger methods can make a lot of difference especially in the less liquid stocks.
