Order Types and Instructions

Use the order type to set execution behavior, then choose time in force and any post-only or reduce-only instruction. The exchange contract determines which combinations are available.

Market and Limit Orders

Type	Example	Behavior
Market buy	Buy 1 BTC at available prices	Takes eligible sell-side liquidity; the average fill price depends on depth
Limit buy	Buy 1 BTC at 77,000 USDT	Executes at 77,000 or lower; an unfilled remainder follows the time-in-force instruction
Limit sell	Sell 1 BTC at 77,100 USDT	Executes at 77,100 or higher

A displayed quote covers only the quantity available at that price. Review depth and fees for the order size you intend to trade.

Post-Only

Post-only requests resting maker liquidity. If the best ask is 77,001 USDT, a post-only buy at 77,001 would cross the spread and may be rejected or cancelled. A buy at 77,000 can rest if the book still permits it when the exchange receives the order.

The documented rejection is POST_ONLY_WOULD_TAKE. Refresh the book before choosing a new quote. Maker fees and rebates come from the account’s fee schedule.

Reduce-Only

Reduce-only constrains an order to closing exposure. For a 1 BTC long position, a filled 0.4 BTC reduce-only sell leaves 0.6 BTC long. Reconcile the remaining position before submitting another exit, especially if other exits are already open.

Time in Force

Instruction	What Happens to the Remainder
GTC — Good Till Cancelled	Remains open until filled, cancelled, or ended under exchange rules
IOC — Immediate or Cancel	Cancels any quantity that cannot execute immediately
FOK — Fill or Kill	Requires the full quantity to execute immediately; otherwise the order is cancelled

Example: a 1 BTC IOC limit buy finds 0.6 BTC within its limit. It fills 0.6 BTC and cancels 0.4 BTC. A FOK order for the same size needs enough eligible liquidity for the full 1 BTC.

See Take Profit & Stop Loss for conditional orders and Order Requests for fields and supported combinations.