In perpetuals, a stop order is not just “a level on the chart.” Every stop/conditional order has a trigger price: the price source the exchange uses to decide the condition has been met. If the trigger source is mismatched, your stop can fire on a brief wick even though you were watching a different reference.
Many exchanges allow choosing the trigger source as Last Price, Mark Price, or Index Price. Bybit explicitly notes that conditional orders can use different reference prices such as Last/Mark/Index.
OKX also describes choosing last/mark/index as the trigger price for stop orders.
Deribit similarly allows mark/index/last as trigger prices for stop orders.
From here, it’s pure execution logic.
What Actually Happens When a Stop “Triggers”
Separate two steps:
- Trigger: your chosen trigger price source hits the threshold.
- Execution: after triggering, a market or limit order is placed, and the market determines the fill.
So the trigger source controls when the stop activates, while the order type controls how you get filled.
Last, Mark, Index: How They Differ for Stops
Last Price
The most recent traded price—the candle price. Pro: your stop triggers close to what you see on the chart. Con: last price is more prone to brief prints and wicks in thin books.
Mark Price
A fair reference used by the risk engine. Binance explains Mark Price as an estimated fair value used to reduce unnecessary liquidations and monitor risk.
On Binance, stop triggers commonly offer Last vs Mark, with dedicated guidance on when to use each.
Pro: fewer false triggers on wicks. Con: can trigger later than last price.
Index Price
A spot-anchored reference. It is useful when you want your stop tied to the underlying spot index rather than a derivatives dislocation. Bybit/OKX/Deribit all document index as a trigger option in relevant order types.
The Most Common Beginner Mistake: Mixing Up Stops and Liquidations
A stop is your voluntary exit. A liquidation is a forced risk procedure, and on futures it is typically tied to Mark Price.
Binance explicitly notes that using Last Price as a stop trigger keeps the stop closer to expected execution, but it does not prevent liquidation because liquidation price is based on Mark Price.
If your margin is already tight, the fix is not “a different trigger,” but reducing exposure: smaller size, lower leverage, more margin, or an earlier exit.
How to Choose a Trigger Price: A Practical Rule Set
Goal A: Exit based on the candle chart
Use Last Price as the trigger—accept that wicks can trigger it.
Goal B: Avoid wick-based false triggers
Use Mark Price as the trigger. It’s the conservative choice in fast conditions.
Goal C: Anchor to spot reality during dislocations
Use Index Price as the trigger, especially when perps drift away from spot.
Stop-Market vs Stop-Limit: What to Use
- Stop-Market: higher exit certainty, potentially worse fill due to slippage.
- Stop-Limit: price control, but you may not exit if the market runs through your limit.
In high volatility, certainty is often more valuable than a perfect price.
A Simple Checklist Before Every Entry
- Confirm your selected trigger price (Last/Mark/Index) in the UI.
- Place stops where the trade thesis breaks—not right above liquidation.
- In high volatility, shift to a more conservative trigger (often Mark or Index) and reduce risk size.
- If the market is overheated, don’t “solve it with a stop”—solve it with exposure and margin.
FAQ
Why did my stop fire even though the candle barely touched the level?
Most often because your trigger was Last Price and a brief print hit the threshold.
Can I avoid stops firing on wicks?
Yes—use Mark Price or Index Price as the trigger if your exchange supports it.
Why didn’t my stop prevent liquidation?
Because liquidations reference Mark Price, and a last-price stop trigger is not a liquidation shield.
Which is better: stop-market or stop-limit?
Stop-market for guaranteed exits; stop-limit for price control with execution risk.
Does using Mark Price as a trigger worsen execution?
The trigger affects activation timing; execution depends on order type and liquidity.
Conclusion
In perpetuals, a stop is not just a line—it’s a process: which price triggers it and how the exit order is placed. If you want predictable behavior during volatility, start with the right trigger source (Last/Mark/Index) and a realistic choice between stop-market and stop-limit. That’s basic risk discipline in derivatives.