The moment usually arrives during a fast-moving market. A trader placed a stop loss at $10.00, the stock gaps down to $9.40, and the fill comes back at $9.38. Suddenly the question that seemed settled — "where will I get out?" — turns out to have a more complicated answer than expected.
A stop loss order is an instruction to exit a position once price reaches a specified level. The core idea is straightforward: limit how much a trade can move against you before the market forces an exit. But the mechanism underneath that simple idea has meaningful variations, and each one behaves differently under pressure.
The most common version is the standard stop-market order. Once price touches your stop level, the order converts into a market order and executes at whatever the next available price happens to be. In a liquid, steadily moving market this usually means a fill very close to the stop. In a thinly traded stock or during a sharp news-driven spike, the gap between stop price and fill price can be substantial.
The stop-limit order is the alternative most traders reach for when they want more control. Here, the stop level triggers the order, but instead of becoming a market order it becomes a limit order — meaning it will only fill at your specified limit price or better. On a $10.00 stop, a trader might set a $9.90 limit. If price gaps past $9.90, the order simply does not fill. Protection from a bad fill comes at the cost of possibly getting no fill at all.
A trailing stop adds a dynamic element. Rather than a fixed price, the stop level moves with the market in your favour by a set amount — say, $0.50 or 2%. If a position rises from $10.00 to $12.00, a $0.50 trailing stop now sits at $11.50. The stop only moves in one direction, locking in gains as price extends. It does not retreat if price pulls back.
Execution risk — the difference between intended exit and actual exit — is the thread connecting all three types. Slippage, as this gap is formally known, is influenced by instrument liquidity, time of day, and news events. Traders who want a deeper foundation on order mechanics can read the full breakdown at Investopedia's stop-loss order guide, explore how slippage is defined and measured, or review the broader context of exchange order types on Wikipedia.
Every stop loss is a negotiation between the price you want and the price the market will give you. Know which type you're placing before the trade is open, not after it's gone wrong.
This content is for educational purposes only and does not constitute financial product advice. Past performance is not indicative of future results. Profit Logic Ltd (ACN 688 669 936) accepts no responsibility for errors or omissions in this content or anywhere on this website. Always seek advice from a licensed financial adviser before making investment decisions.