When placing a limit order, you can choose different order execution strategies to set the order's validity and execution method. With GTC, IOC and FOK orders, you can specify how long the order remains valid before it's executed or expires, enabling you to better implement your trading strategies.
Here's a detailed breakdown of these three order types and some applicable scenarios:

1. GTC (Good-Till-Cancelled):
- Definition: This type of order remains valid until it's fully filled or manually canceled.
- Suitable Scenario: Ideal for users who don't need an immediate fill but want to buy or sell at a specific price.
- Example: If you want to go long on BTC at $69,800, set a GTC order to buy at $69,800. When the market price reaches or falls below $69,800, your order will be filled. The order will remain valid until it's fully filled or manually canceled.

2. IOC (Immediate-Or-Cancel):
- Definition: This type of order needs to be fully or partially filled right away. Any unfilled portion will be automatically canceled.
- Suitable Scenario: Ideal for users who need quick execution, especially in rapidly changing market conditions.
- Example: If you want to buy 5 BTC at $69,800 but your order can only immediately fill 3 BTC at that price, the remaining 2 BTC will not be filled and will be canceled.

3. FOK (Fill-Or-Kill):
- Definition: This type of order must be fully filled right away, or it'll be completely canceled. Partial fills are not allowed.
- Suitable Scenario: Ideal for users who need to ensure their entire order is filled immediately, usually for more precise trading strategies.
- Example: If you plan to open a 10 BTC position at $69,800 but the market can only fill 8 BTC at that price, your order won't be filled at all and the entire order will be canceled.