Tools
Position Sizing Calculator: Never Risk More Than You Can Lose
Summary
Position sizing is the first risk control, not a final detail. A consistent sizing model can reduce portfolio damage from inevitable losing streaks.
Market Context
Most blowups come from sizing errors, not from one bad chart read. In fast markets, position size amplifies slippage, emotional pressure, and decision fatigue.
The Thesis
Use a position sizing calculator before every trade. Risk should be determined from account size and stop distance, then translated into share or contract quantity.
Trade Structure (Paper)
Baseline framework:
- Account risk budget per trade (for example, 1% of equity)
- Technical or structural stop distance
- Quantity = max risk amount divided by stop distance
This keeps expected loss bounded before execution begins.
What Happened
Across paper tests, fixed-risk sizing reduced volatility of outcomes and prevented single-trade damage from compounding into deep drawdowns.
Post-Mortem
What worked: pre-trade sizing rules and hard caps by instrument.
What failed previously: adding size mid-trade without updating total-risk assumptions.
Behavioral Notes
Sizing discipline is hardest after a loss when the urge to “make it back” appears. A calculator externalizes the decision and reduces narrative-driven overrides.
FAQ
How much should I risk per trade?
Many traders use 0.5% to 2% of account equity per trade. The exact number should match your strategy variance and drawdown tolerance.
Why is position sizing more important than entry timing?
Entries can be wrong often. Sizing determines whether those errors remain survivable.