What a stop loss is
A stop loss is an order that closes your trade automatically when price hits a defined level. Its purpose is to cap your loss at an amount you decided in advance, so a single trade can't damage the account in a way you didn't consent to.
Why every trade should have one
Without a stop, a losing trade has no defined end. Price can move against you further and further, and the human tendency is to hold on hoping it comes back rather than accept the loss. That hope has a name — it's called drawdown, and it's how most retail accounts end. A stop takes the decision out of your hands at the moment you're least equipped to make it well.
Set the stop when you enter, not later, and honour it when it hits. Every trade. No exceptions.
Technical versus arbitrary stop placement
A technical stop is placed at a level that would meaningfully invalidate the reason you took the trade — beyond a recent swing high or low, past a session high, on the far side of a level the market has been respecting. If price gets there, the trade idea is genuinely wrong.
An arbitrary stop is placed at a round number of pips ('I'll use 20 pips') or at a comfortable pound figure ('£50 feels okay to lose') with no reference to what's happening on the chart. It might be tight, wide, or somewhere in between, but it isn't attached to anything in the market. When it gets hit, you learned nothing.
Place the stop technically, then size the trade so the resulting loss matches your risk rules. Never do it the other way round.
Common stop-loss mistakes
- Placing the stop where the loss feels acceptable rather than where the idea is wrong
- Setting a very tight stop to enable a larger position size
- Placing stops on obvious round numbers where liquidity concentrates
- Moving the stop further away when price approaches it
- Removing the stop entirely because 'the trade will come back'
That last one is the account killer. The moment you remove a stop, the trade has no upper bound on loss, and every previous discipline in your process becomes irrelevant.
Giving trades enough room
New traders default to tiny stops because they feel safer. In practice, they're not. A ten-pip stop sitting in the middle of normal market noise will get picked off repeatedly, even when your idea is right. A twenty-five-pip stop placed beyond a genuine level will often survive the same wick and let the trade develop.
'Tight' is not the same as 'safe'. Safe is a stop that price only reaches when your idea is actually wrong.
Accepting small losses
Every trader has to internalise a hard truth: taking small planned losses is the price of being in this business. There is no strategy without them. A trader who cannot accept a small loss will eventually take a large one, because the pressure to avoid the small loss builds until something breaks.
Think of each loss as an expected cost of doing business, not as a failure. That reframe alone changes how you trade.
Why moving stops emotionally often increases losses
The urge to widen a stop when price gets close is one of the strongest impulses in trading. It always feels reasonable in the moment. 'The market's just wicking, I'll give it a bit more room.' The result, on average, is that a small planned loss becomes a large unplanned one — and worse, you've trained yourself that stops are negotiable.
The rule is simple. The stop was placed when you were calm and thinking clearly. Trust past-you. Let it hit if it hits.
Key takeaways
- Every trade needs a stop, set on entry, honoured on hit
- Base the stop on market structure, not on comfort
- Size the position from the stop, never the stop from the position
- Tight stops in random places lose more than wider stops in the right places
- Never move a stop further away — that turns small losses into large ones