How to Set a Stop-Loss That Actually Protects You

A stop-loss is the price at which you admit a trade idea was wrong. Setting it well is less about the exact number and more about deciding it before you enter.

Put the stop where the idea is invalidated

A stop should sit at a level that, if reached, means the setup no longer makes sense — below the support you bought into, or above the resistance you shorted. A stop placed at an arbitrary percentage ("I always use 5%") ignores the chart and tends to get hit by normal noise.

Size the position from the stop, not the other way round

Once the stop is set, work out how much you are willing to lose if it is hit — many traders use 1–2% of their account per trade. Then:

position size = (account × risk %) ÷ (entry − stop)

A wide stop means a smaller position; a tight stop allows a larger one. The money at risk stays the same.

Don't move it further away

Moving a stop away from price to "give the trade room" turns a planned small loss into an unplanned large one. Moving it toward price as targets are hit — for example to break-even after the first target — is a different thing and locks in the plan.

Checklist

• Stop decided before entry
• Placed at an invalidation level, not a round percentage
• Position sized so a stop-out costs a fixed slice of your account
• Only ever moved in the direction of profit

This article is educational and not financial advice.