How stop loss orders work and where they can fail
A standard stop loss becomes a market order when the trigger price trades, which means the fill price can be worse than the trigger during fast or gapping markets. This difference, often called slippage, is a normal feature of market-triggered orders, not a malfunction. Some brokers offer guaranteed stop losses on certain instruments, usually for an extra charge, while others offer stop-limit variants that may not fill at all in a gap. Understanding which type you are placing is essential before you rely on it as protection.
- A triggered stop typically fills at the next available price, which can differ from the trigger.
- Price gaps over weekends, news events or market opens can produce significant slippage.
- Guaranteed stops, where offered, usually carry a fee and instrument restrictions.
- Stop-limit orders control fill price but may remain unfilled if the market gaps past the limit.


