Spot Market Orders: Partial Fills and Expiration When Liquidity Runs Out
Summary
This exchange note explains how spot market orders consume the best available prices and liquidity until the requested quantity is filled or the order book cannot supply more. It distinguishes insufficient account balance, which causes rejection, from insufficient market liquidity, which can result in a partial fill followed by expiration of the unfilled remainder. The response status is shown as expired in the latter case.
Example API and user-stream messages illustrate the sequence: an order is accepted, fills in multiple trades, then expires after available liquidity is exhausted. The examples also show execution and order status fields changing through the lifecycle, alongside cumulative executed quantity and account balance updates. The figures and commissions are explicitly fictional, and the explanation is limited to spot exchange behavior. It describes exchange mechanics rather than offering a trading strategy or claims about execution quality across venues.
Key ideas
- A spot market order takes available liquidity at the best prices until filled or liquidity runs out.
- An insufficient balance causes rejection, while inadequate book liquidity can leave a partially filled order.
- The unfilled remainder expires when the exchange cannot provide more liquidity.
- API responses and user-stream execution reports expose fill progress and final expiration status.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.