A stop can trigger after price has already moved beyond the stop level. It does not normally need a trade at the exact stop price: the broker applies its specified trigger condition at or beyond the threshold. The resulting execution can be much worse than the price you planned.

A Gap Does Not Guarantee a Particular Fill

Suppose you hold 100 shares bought at $50 with a sell stop at $48. The next eligible market price is $42. A stop-market order can activate and execute around the available prices; it is not promised a $48 or even a $42 fill. If the average fill is $41.80, the price loss is $820 rather than the planned $200.

FINRA explains this stop-price versus execution-price risk. A stop-limit can instead remain unfilled when the market trades below its sell limit.

Find Out What Happened

Check the order log for submission, acceptance, trigger, partial fills, cancellations and rejection messages. Compare the broker's trigger reference and eligible sessions with the chart. A displayed overnight move may occur outside the session covered by your order. A trading halt can prevent execution until trading resumes.

Distinguish an accepted order that filled badly from one that never activated or was rejected. Those problems require different fixes.

Reduce Exposure to Gaps

Being flat before a scheduled closure removes that position's subsequent overnight exposure, provided the exit actually completes. It does not remove intraday halts, sudden news or execution gaps while you are still trading.

Smaller positions reduce the currency impact of a given adverse move. Use several stress scenarios rather than labeling one historical move the worst possible gap. Check known earnings and economic events before deciding whether to retain exposure; unexpected events remain possible.

Protection Has Specific Terms

If a broker offers a guaranteed stop, read its eligibility, charges and contractual conditions. Do not assume an ordinary stop has that protection. Options hedges also require a separate assessment of contract coverage, strike, expiry, premium and exercise mechanics; merely holding an option is not a blanket guarantee against loss.

In an evaluation account, distinguish simulated execution from a live brokerage fill and check how the provider calculates a breach. Your own stop budget and the account's loss boundary may measure different things.

Risk Disclaimer: Trading involves substantial risk of loss. Past performance is not indicative of future results. See our full risk disclaimer.