Exchange Self-Trade Prevention Modes and Order Outcomes

Summary

This FAQ explains how an exchange prevents a user’s orders, or orders from accounts sharing a trade group, from matching against each other. It describes the available outcomes: allow the match, expire the taker or maker order, expire both, decrement both orders’ quantities, or transfer prevented quantities between accounts in certain group trades. Usually the taker’s configured mode governs; transfer requires both orders to select that mode.

The document also explains prevented-match records, cumulative and per-event prevented quantities, order status after prevention, and how symbol configuration determines permitted modes and defaults. API response examples illustrate these concepts, including the remaining-quantity calculation and expiration status. This is an operational reference for order handling and execution behavior, rather than a trading strategy. The fictional examples clarify mechanics but do not establish how any particular live market is configured.

Key ideas

• A self-trade can involve one account or separate accounts sharing a trade group identifier.
• The taker’s prevention mode generally determines whether orders expire or have quantities reduced.
• Transfer behavior requires both maker and taker orders to use the transfer mode.
• Prevented matches are recorded separately from trades, and affected orders report prevented quantities.
• Symbols can restrict available prevention modes and define a default for orders without an explicit setting.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.