Take-profit orders: triggers, partial fills and an open remainder

A target can be reached without closing everything

Suppose a long position entered at 100 has a take-profit trigger of 110 and a sell limit of 109. After triggering, only the quantity that finds buyers at 109 or better can execute. A reversal to bids below 109 can leave some or all of the order unfilled.

A market-style take-profit trades execution urgency against less precise pricing, subject to the venue’s protections. Neither version guarantees net profit after all costs.

Keep the closing size consistent with the position

If a trader manually closes half the position, an older exit instruction may be too large. Reduce-only constrains the resulting exposure. The cited dYdX implementation resizes conditional reduce-only orders at triggering; other venues can reject or handle them differently.

Check the completed trade

Read trigger status, executed quantity, average fill price and remaining position separately. Multiple take-profit and stop orders also need explicit cancellation or linkage behavior; the mere existence of two orders does not establish that filling one cancels the other.