Position Sizing: How Much to Risk Per Trade (and Why 1% Survives What 5% Doesn’t)
Position sizing: how much to risk per trade (and why 1% survives what 5% doesn’t)
Strategy gets the glory. But the number in the lot-size box decides whether your edge ever gets the chance to show up.
Two traders take the exact same trades for a year — same entries, same exits, same win rate. One finishes up 40%. The other blows the account in March. The only thing they did differently was decide how much to risk on each trade.
Position sizing is the most under-rated decision in trading, and it’s the one you make most often. Get it right and a cold streak is a dull fortnight. Get it wrong and a perfectly normal run of losses ends you. Here’s how to size so your edge actually survives long enough to pay you.
What “risk per trade” actually means
Risk per trade is the amount of your account you lose if a single trade hits its stop — not the position size, not the margin, the loss. You express it as a percentage of equity. The widely cited ceiling is 1% per trade; plenty of professionals run lower.
On a €25,000 account, 1% risk means you lose €250 if the stop is hit. Whether that’s a 0.2-lot position or 2 lots depends entirely on where your stop sits. The percentage is the constant; the lot size is whatever math makes that percentage true.
The formula — memorise this one
Worked example: €25,000 account, 1% risk = €250. You’re shorting GBPUSD with a 25-pip stop, at roughly €8 per pip per lot. €250 ÷ (25 × €8) = 1.25 lots. Widen the stop to 50 pips and the same €250 of risk means 0.625 lots — half the size for double the stop. The stop defines the size, not the other way round.
Most blown accounts come from doing this backwards: pick a size that “feels right,” then set a stop to fit. That isn’t sizing to your risk — it’s sizing to your hope.
Why 1% survives what 5% doesn’t
Losing streaks aren’t bad luck; they’re a mathematical certainty. With a 50% win rate, a run of six losses in a row shows up roughly once in every sixty-odd sequences — which, over a trading year, means regularly. The question isn’t if. It’s what the streak does to you when it lands.
| Losing streak | Risk 1% | Risk 3% | Risk 5% |
|---|---|---|---|
| 5 losses in a row | −4.9% | −14% | −23% |
| 10 losses in a row | −9.6% | −26% | −40% |
| Gain needed to recover the 10-loss hole | +11% | +36% | +67% |
At 1% risk, ten straight losses costs about 9.6% — irritating, fully recoverable, an afternoon’s problem. At 5% risk, that identical streak costs 40% of the account, and the recovery maths is brutal: a 40% hole needs a 67% gain just to climb back to flat. Same trades. Same edge. One trader is mildly annoyed; the other is on life support — and far more likely to start revenge trading to “fix” it.
Risk of ruin: the number nobody checks
Every per-trade risk level carries a risk of ruin — the probability that a normal losing streak wipes you out entirely. Push risk per trade up and that probability climbs frighteningly fast; with a modest edge, risking 5–10% per trade can make eventual ruin close to certain, no matter how good your strategy is. Cutting risk per trade is the single most powerful lever you have on survival, and it costs you nothing but patience.
Size down when you’re cold
Your risk percentage doesn’t have to be fixed. A simple, powerful rule: when you’re in a drawdown, cut risk — halve it to 0.5% until you string together a few clean, plan-following trades. You protect capital when you’re trading worst and scale back up only once you’ve earned it. It’s the opposite of what instinct screams at you to do, which is exactly why it works.
Where RiskLogged fits
Sizing discipline is easy to hold when you’re calm and almost impossible to hold mid-session, when a “high-conviction” setup tempts you into two or three times your normal size. RiskLogged’s TradeGuard checks every position against your own sizing rule as you place it — pips and euros aligned — and flags an oversized trade before it’s the one that turns a bad day into a bad quarter.
Key takeaways
- Risk per trade is the loss you take if your stop is hit — set it as a % of equity, capped around 1%.
- Size = (Account × Risk%) ÷ (Stop distance × point value). The stop sets the size.
- Ten losses in a row costs ~10% at 1% risk and ~40% at 5% — and 40% needs +67% to recover.
- Higher per-trade risk raises your risk of ruin sharply; lowering it is the best survival lever you have.
- Cut size during drawdowns; scale back up only after you’re trading well again.
Size every trade to your rule — automatically.
RiskLogged checks your position size against your risk plan live on MT5 and flags the trades that break it. Private beta — Windows + MT5, local-first.
Join the beta waitlist →Educational content only. Pip values are approximate and vary by instrument and account currency. Nothing here is financial advice. Trading leveraged products such as forex and CFDs carries a high risk of loss and isn’t suitable for everyone.
