How to enable "Post-Only" for limit orders? (Execution Settings)

Understanding Post-Only Mode

1. Post-Only is an order execution setting that ensures a limit order is placed only as a maker—never as a taker.

2. When activated, the exchange checks whether the order would immediately match against existing orders in the order book.

3. If a match would occur, the order is rejected instead of being executed, preserving the maker status and associated fee benefits.

4. This mode prevents unintended market impact and avoids taker fees, especially critical during volatile price movements.

5. It applies exclusively to limit orders; market orders and stop-limit orders cannot be configured as Post-Only.

Platform-Specific Activation Steps

1. On Binance Futures, users toggle “Post-Only” in the advanced order panel beneath the price and quantity fields.

2. Bybit requires enabling “Post Only” via the “Advanced” dropdown before submitting a limit order on the derivatives interface.

3. OKX displays a checkbox labeled “Post Only” next to the “Reduce-Only” option in the order entry section for perpetual contracts.

4. Kraken Pro places the setting under “Order Type Options”, where selecting “Post Only” disables immediate matching logic.

5. Coinbase Advanced Trade surfaces it as a switch titled “Maker Only” in the order form’s execution preferences.

Risk Implications of Misconfiguration

1. Disabling Post-Only unintentionally may cause rapid slippage when liquidity is thin, triggering unexpected fills at worse prices.

2. During flash crashes or sudden squeezes, non-Post-Only limit orders can convert into aggressive market orders if price gaps exceed expected levels.

3. Arbitrage bots often exploit misconfigured orders by front-running with taker liquidity, eroding net profit margins.

4. Repeated rejections due to strict Post-Only enforcement may delay position entry, especially in low-volume altcoin pairs.

5. Some exchanges throttle or rate-limit repeated Post-Only rejections, potentially affecting order submission throughput during high-frequency strategies.

Fee Structure Advantages

1. Maker fees on major derivatives platforms range from −0.01% to 0.02%, while taker fees sit between 0.04% and 0.075%.

2. A single $100,000 contract trade executed as a maker instead of a taker saves between $40 and $75 in fees.

3. Volume-based fee tiers compound this benefit—higher-tier users gain deeper maker rebates, sometimes exceeding 0.025%.

4. On BitMEX legacy, consistent Post-Only usage contributed directly to tier advancement and rebate eligibility.

5. Exchanges like Deribit apply negative maker fees only when orders remain on the book for more than five seconds—Post-Only enforces that minimum resting time.

Frequently Asked Questions

Q: Does Post-Only prevent my order from ever being filled?A: No. It only prevents immediate matching. The order remains active in the book until price movement brings it into alignment with opposing liquidity.

Q: Can I combine Post-Only with Time-In-Force options like IOC or FOK?A: No. Post-Only is incompatible with IOC (Immediate Or Cancel) and FOK (Fill Or Kill); those modes inherently prioritize execution over maker status.

Q: Why does my Post-Only order show “Rejected” even when the price hasn’t moved?A: Hidden liquidity, iceberg orders, or internal matching engines may trigger silent taker execution paths—Post-Only rejects any scenario where instant fill is possible, even if not visible in public depth.

Q: Is Post-Only available for spot margin trading?A: Yes, but availability varies. Binance Spot Margin supports it; KuCoin Spot does not. Always verify per trading pair and account type before submission.