| Name | Type | Description | Notes |
|---|---|---|---|
| contract | string | Futures name, currently only supports perpetual futures for BTC and ETH with USDT. | [default to undefined] |
| size | string | Futures quantity, representing the initial order quantity, not involved in actual settlement. | [default to undefined] |
| left | string | Unfilled contract quantity, involved in actual calculation | [default to undefined] |