Finance & trading
How many shares should you buy for a 1% risk trade?
How much to invest per trade based on capital, risk % and stop loss.
Quick answer
Units = (capital × risk%) ÷ |entry − stop loss|. €10,000 capital, 1% risk (€100), entry €50, stop €47: risk per unit = €3 → 100 ÷ 3 = 33.33 units. Position value = 33.33 × €50 ≈ €1,667 — only 16.7% of capital, but max loss is capped at €100.
Units to buy
33.33
- Position value
- ,666.67
- Maximum risk
- 00.00
- Risk per unit
- $3.00
How it works
Position sizing separates professionals from gamblers. Risk 0.5–2% of capital per trade so a string of losses does not wipe the account. Wider stops mean fewer units for the same dollar risk — do not widen stops just to buy more shares.
Write entry, stop and size in a trading journal before you click buy — revising the stop after price moves against you is how accounts bleed. Study drawdown math and Kelly variants in a trading risk management book before raising risk above 1%. General guidance only — not investment advice; never risk capital you cannot afford to lose.
The calculation assumes the stop fills at the stop, and sometimes it does not. Prices gap — over a weekend, on an earnings release, on news — and a market can reopen well beyond the level you set, so the realised loss exceeds the planned one with nothing malfunctioning. The thinner the instrument and the closer the event, the wider that gap can be. Two consequences for sizing: treat the calculated risk as a best case rather than a maximum, and be aware that carrying a position through a scheduled announcement is a different bet from the one this arithmetic describes.
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Frequently asked questions
What risk percentage per trade?+
Conservative: 0.5–1%. Aggressive: 1–2%. Above 2% per trade, a five-loss streak costs 10%+ of the account — hard to recover psychologically and mathematically. Scale risk down during drawdowns, not up to “win it back”.
Where should I place the stop loss?+
Below technical support (long) or above resistance (short) — not an arbitrary percentage. The stop defines risk; position size adapts to stop distance. Tighter stops are not always better if they get hit by noise before the move develops.
Can I risk more on high-conviction trades?+
Conviction is not edge. Size up slightly (e.g. 1.5% vs 1%) if you must, but doubling risk on "sure things" is how accounts blow up — markets disagree often. Track conviction trades separately; you may find they underperform your rule-based sizes.
Position size for forex lots?+
Same formula: risk amount ÷ (stop in pips × pip value per lot). Pip value depends on pair and lot size (standard lot = 100,000 units). Many brokers offer position-size calculators built in — cross-check with this tool before placing the order.
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