Risking a small, fixed percentage per trade is the simplest way to survive long losing streaks. Here is the maths behind the 1% rule and when to adjust it.
Ask experienced traders what keeps them in the game and most will say position sizing, not entries. The "1% rule" is the most common version: never lose more than 1% of your account on a single trade.
Why such a small number?
Every strategy has losing streaks, and they are longer than most people expect. Look at what consecutive losses do to an account at different risk levels:
- 1% per trade: 10 losses in a row leaves about 90% of the account.
- 2% per trade: 10 losses leaves about 82%.
- 5% per trade: 10 losses leaves about 60%.
- 10% per trade: 10 losses leaves about 35%.
With a 50% win rate, a run of 10 losses somewhere in 1,000 trades is not rare. At 1% you shrug it off. At 10% you are fighting to recover 185%.
Recovery is not symmetrical
A 20% drawdown needs a 25% gain to recover. A 50% drawdown needs 100%. A 80% drawdown needs 400%. Small risk per trade keeps you in the zone where recovery is realistic.
How to apply it
Risk is measured from entry to stop loss, not by lot size alone.
- Decide your risk in money: account x 1%. On a $5,000 account that is $50.
- Measure the stop distance: for example $5 on gold.
- Work out the lot size so that the stop distance costs $50. On XAUUSD, 1 standard lot moves $100 per $1, so a $5 stop costs $500 per lot. $50 / $500 = 0.10 lots.
Most good Expert Advisors can do this calculation for you with a "risk %" input instead of a fixed lot.
When 1% is too much or too little
- Systems without a stop loss (grids, martingales) cannot use this rule directly - their real risk is the whole basket. Treat them with extreme caution and cap the total exposure instead.
- Several strategies at once add up. Five systems each risking 1% on correlated trades can behave like one 5% trade.
- Very high win-rate scalpers sometimes use less, because one bad fill can cost several average wins.
- Small accounts often cannot size down enough because of minimum lot sizes. If 0.01 lots already risks 5%, the account is too small for that strategy.
The real goal
The 1% rule is not magic. The point is to choose a risk level at which the worst realistic losing streak still leaves you able, financially and emotionally, to keep following the plan.
Trading forex and gold carries a high level of risk and may not be suitable for every investor. Past performance and backtests do not guarantee future results. This article is education, not financial advice.