What is the "Reduce-Only" option on Bybit and how does it prevent accidental orders?

Understanding Reduce-Only Mode

1. Reduce-Only is a risk control feature on Bybit that restricts order execution to positions that only decrease or close existing open positions.

2. When enabled, the system automatically cancels any order that would increase position size—whether long or short—regardless of direction or leverage settings.

3. This mode operates at the order level, meaning every individual order submitted with Reduce-Only activated is validated against current position status before routing.

4. It applies uniformly across perpetual and inverse futures contracts but does not affect spot trading or options markets.

5. The flag is enforced server-side, so client-side modifications or API tampering cannot override its logic once triggered.

How Reduce-Only Mitigates Human Error

1. Traders often misjudge entry points during volatile market swings and attempt to add to losing positions without realizing the directional mismatch.

2. A long position holder might accidentally place a buy order thinking it’s a hedge, but Reduce-Only blocks it if no additional long exposure is permissible.

3. In multi-position accounts, overlapping orders from different strategies can conflict; Reduce-Only ensures only net reduction occurs per instrument.

4. Copy-trading users benefit when signal providers enable Reduce-Only, preventing followers from unintentionally opening offsetting positions due to latency or slippage.

5. Manual traders using keyboard shortcuts or mobile interfaces frequently hit wrong buttons—Reduce-Only acts as a final gatekeeper before order matching.

Technical Enforcement Mechanism

1. Before order matching, Bybit’s matching engine checks position delta: if the proposed order increases net exposure, it returns an error code “ReduceOnlyOrderWouldIncreasePosition”.

2. The check includes consideration of partial fills—if a limit order may be partially filled in a way that expands exposure, the entire order is rejected.

3. Cross-margin and isolated-margin accounts both honor Reduce-Only, though margin balance calculations differ slightly between the two modes.

4. Stop-market and take-profit orders inherit the Reduce-Only attribute from their parent position, ensuring conditional logic remains consistent.

5. API users must explicitly set the reduce_only parameter to true; omission defaults to false, making explicit declaration mandatory for safety.

Interaction With Other Risk Parameters

1. Reduce-Only works independently of TP/SL triggers but affects how those orders behave—if a stop order would open a new position, it fails even if price hits the trigger level.

2. Trailing stops retain Reduce-Only behavior dynamically: as price moves, the trailing stop recalculates whether execution would reduce or increase exposure.

3. When combined with Close-All functionality, Reduce-Only ensures all active orders in the batch are evaluated individually—not just the aggregate result.

4. Position mode (Hedge vs One-Way) influences Reduce-Only scope: in Hedge Mode, long and short sides are evaluated separately, while One-Way treats them as a net value.

5. Liquidation engine respects Reduce-Only constraints—no forced liquidation order violates this rule, even under extreme funding rate pressure or index divergence.

Frequently Asked Questions

Q: Does Reduce-Only apply to market orders placed via Bybit’s mobile app?Yes. All order types—including market, limit, stop-market, and stop-limit—are subject to Reduce-Only validation regardless of interface or device.

Q: Can I disable Reduce-Only after enabling it for a specific order?No. Once an order is submitted with reduce_only=true, the setting is immutable for that order lifecycle. Cancellation and resubmission are required to change it.

Q: What happens if my position is already zero when I submit a Reduce-Only order?The order is immediately rejected with error code 30037 (“ReduceOnlyOrderOnZeroPosition”), preventing phantom entries or unintended margin usage.

Q: Do trailing take-profit orders respect Reduce-Only when the trailing distance adjusts?Yes. Each re-evaluation of the trailing stop recalculates exposure impact, and execution is blocked if the updated trigger would expand position size.