How to Set an OKX Futures Stop-Loss That Closes Only Part of Your Position?

Understanding Partial Position Closure in OKX Futures

1. OKX Futures supports partial position closure via the ordType=take_profit_stop or ordType=stop_market order types when combined with explicit sz parameters.

2. Unlike full-position liquidation triggers, a stop-loss order with a defined size does not require the entire open position to be active at the time of execution — it only acts on the quantity specified in the request.

3. The posSide field must match the side of the existing position (long or short), otherwise the order will be rejected with error code 51000.

4. When placing such an order, OKX validates whether the requested sz is less than or equal to the current available position size; exceeding it results in immediate rejection.

5. Partial stop-loss orders appear as independent entries in the order history and do not modify the original position’s average entry price or margin usage for the remaining portion.

Step-by-Step Order Construction Using python-okx

1. Initialize the TradeAPI with proper credentials and set flag='0' for real trading or flag='1' for demo mode.

2. Retrieve current position details using AccountAPI.get_positions() to confirm pos, avgPx, and posSide.

3. Calculate the exact sz value as a string representing the number of contracts or base asset units to close — e.g., '0.05' for BTC-USDT-SWAP if holding 0.1 BTC.

4. Construct the stop-market order payload with required fields: instId, tdMode='isolated' or tdMode='cross', side, ordType='stop_market', sz, stpAct='close', and slTriggerPx.

5. Submit via TradeAPI.place_order(). A successful response returns ordId, state='live', and accFillSz equal to zero until triggered.

Key Parameter Constraints and Behavior

1. The slTriggerPx must lie outside the current market price for long positions (below) and short positions (above); otherwise, the order triggers immediately upon submission.

2. If tdMode='isolated', the slTriggerPx is validated against the isolated margin balance and position leverage — insufficient margin causes rejection before placement.

3. Orders with ordType='stop_limit' require both slTriggerPx and slOrderPx; they do not support partial closure unless explicitly sized — same sz logic applies.

4. Triggering does not guarantee execution at slTriggerPx; market orders execute at best available price after trigger, which may differ significantly during high volatility.

5. No automatic adjustment occurs if the underlying position size changes between order placement and trigger — the order executes only the originally declared sz, even if the position has since been reduced manually.

Verification and Post-Execution Monitoring

1. Use TradeAPI.get_order(instId, ordId) to poll status until state='filled' or state='canceled'.

2. Cross-check executed size against fillSz in the order detail response — this value reflects actual closed quantity, not requested sz.

3. Query updated position state via AccountAPI.get_positions() to verify remaining pos and recalculated availPos.

4. Inspect TradeAPI.get_fills() with appropriate time filters to retrieve trade-level execution data including px, sz, and fee.

5. Enable WebSocket private channel positions and orders to receive real-time updates without polling overhead.

Frequently Asked Questions

Q: Can I place multiple partial stop-loss orders targeting different portions of the same position?A: Yes. Each order operates independently as long as total sz across all live stop orders does not exceed current pos. OKX does not enforce cumulative validation at placement time.

Q: Does a partial stop-loss order affect my position’s liquidation price?A: Only the remaining unclosed portion influences liquidation calculations. The closed segment is removed from margin utilization and risk exposure immediately upon fill.

Q: What happens if my position is partially closed by another order before the stop-loss triggers?A: The stop-loss still executes its originally specified sz. If that amount exceeds the updated pos, the order fails with error code 51003 ('Insufficient position size').

Q: Is there a way to cancel only one of several active partial stop-loss orders?A: Yes. Each order has a unique ordId. Call TradeAPI.cancel_order(instId, ordId) with the specific ID to remove it without affecting others.