How to set a stop-loss

Every trader knows they should use a stop-loss, yet cutting a loss is one of the hardest things to do in practice. The beauty of a stop-loss is that it removes the decision from the heat of the moment: you decide where you are wrong before you enter, set the order, and the market does the rest. Getting the placement right, and then sizing the trade around it, is the whole skill. Here is how.

What a stop-loss is

A stop-loss is an order that closes your trade automatically at a price you choose, capping the loss. Open a buy trade and you set the stop below your entry; if price falls to that level, the position closes for you, no watching the screen, no agonising. It is the single most important tool for keeping any one trade from doing serious damage.

Place it on the chart, not on your feelings

The most common mistake is placing a stop where the loss “feels” acceptable. Instead, place it where your trade idea would genuinely be proven wrong. Two reliable approaches:

• Structure-based, just beyond a recent support or resistance level, so the stop only triggers if that level actually breaks.
• Volatility-based, a set distance derived from how much the market normally moves, so the stop sits outside the everyday noise.

Both put the stop at a level that means something, rather than at an arbitrary number.

Size the trade around the stop

This is the step beginners skip. Once you know where the stop goes, the distance from entry to stop is your risk per unit. Combine that with the 1% rule, never risking more than 1% of your account, and your position size is fixed: it is whatever makes that stop distance equal 1% of your balance. A wider stop means a smaller position; a tighter stop lets you trade a little larger. The stop decides the size, not the other way round.

Trailing stops

A trailing stop follows price as a trade moves in your favour but never moves back. If you are long and price rises, the stop trails upward at a fixed distance, locking in profit; if price then falls by that distance, the trade closes. It is a simple way to protect gains on a winner while still giving it room to run. Useful, but not essential, a fixed stop placed well does the core job.

Mistakes to avoid

• Stops too tight, placed inside normal market noise, so you get closed out right before the move you expected.
• Moving your stop wider mid-trade to avoid a loss, this defeats the entire purpose and turns a small loss into a big one.
• No stop at all, hoping the market comes back. Hope is not a risk strategy.
• Round-number stops that everyone can see, sometimes better to sit just beyond an obvious level.

The habit that matters

Set your stop before you enter, size the position so that stop equals about 1% of your account, and then leave it alone. The discipline of never widening a stop, and always having one, will do more for your results than any indicator. A stop-loss only works if you let it work.