There are three types of auxiliary functions (order strategies) for limit orders: GTC, FOK, and IOC.
A brief description of each feature is as follows:
- GTC: Fill in as much as you can and keep the remaining orders.
FOK: Fills only when conditions are fully met, orders are canceled if they cannot be filled immediately.
- IOC: If there is an order that meets the conditions, it will be executed even if it is partly, and the remaining order will be canceled. I think that each explanation is difficult to understand with text alone, so please refer to the specific examples and tables at the bottom of the page.
１．GTC（Good Till Canceled）
GTC is an order strategy that remains active until the order is fully executed or manually canceled by the trader.
GTC allows you to wait for all orders to be completed at a specified price and gives you the flexibility to cancel unfilled orders at any time.
GTC can be said to be a useful feature for traders who want to cancel limit orders themselves.
２．FOK（Fill or Kill）
FOK is an order strategy contingent on the immediate execution of all orders at or above the order price.
If you place an order with FOK and it is not executed according to the conditions you set, the order will be canceled immediately.
３．IOC（Immediate or Cancel）
IOC is an ordering strategy that fills as many orders as can be processed immediately and cancels unfilled orders.
From here, I will explain each of GTC, FOK, and IOC while looking at specific examples.
When the market conditions are as shown in the table below, when a trader places an order in GTC, FOK, and IOC with an order volume of 10,000 and an order price of 11,800, let's see the results of each execution.
1. If you place an order with GTC, only 5,000 trading volumes can be filled at a price of 11,800, so this amount will be filled.
Since the trader's order volume was 10,000, this order is also kept because there is still 5,000 remaining order volume.
2. If you place an order with FOK, there is no transaction in the market (order book) that can be executed at a price of 11,800 and an order volume of 10,000, so this order will not be partially executed and will be canceled.
3. If you place an IOC order, only 5,000 trading volumes can be executed at a price of 11,800, so this amount will be executed.
We still have 5,000 remaining orders, but this order will be canceled.