What is the 357 rule in trading?

The 3-5-7 rule is the most practical risk management framework traders use. It's simple enough to implement on day one and sophisticated enough to scale to professional-level accounts.

The Three Components

3% Rule: Single Trade Risk

Never risk more than 3% of your total account on one trade.

Example: Account = $10,000. Maximum risk per trade = $300.

This doesn't mean betting $300. It means your worst-case scenario on the trade should lose no more than $300. You calculate this using stop-losses.

If you buy YES at $0.50 and set a stop-loss at $0.30, you're risking $0.20 per share. To stay within 3% risk ($300), you can buy max 1,500 shares ($0.20 × 1,500 = $300 risk).

The 3% limit prevents any single trade from crippling your account. Even if you're right 50% of the time, your losses are capped and manageable.

Why 3%? Studies show traders can consistently execute with this sizing. Beyond 3%, emotional control degrades. You start making irrational decisions to recover losses.

5% Rule: Total Portfolio Exposure

Keep all open positions combined under 5% total account exposure.

Example: You have three open trades risking $300, $200, and $100 respectively. Total = $600. Your 5% threshold on a $10,000 account = $500 maximum. You're over. Close one position or reduce sizes.

The 5% rule prevents concentration risk. You might be right on 3 out of 4 trades, but if one volatile position swings hard against you, you don't lose the entire account.

This forces diversification across markets, timeframes, and thesis.

Why 5%? If your 5 best trades all go wrong simultaneously, maximum loss is 5%. Extremely rare for unrelated markets to all move against you, but it happens during black swan events (market crashes, geopolitical shocks).

7% Rule: Profit Target and Ratio

Target at least 7% profit, or more commonly, maintain a 7:1 reward-to-risk ratio.

If you're risking $100, your profit target should be $700. This ratio forces you to only take trades with asymmetric payoffs.

Example: Market is uncertain. You estimate 60% chance of YES winning. YES trades at $0.40. If YES resolves as YES, you make $0.60 per share (a 150% return). If it resolves as NO, you lose $0.40 per share (a 100% loss).

Risk-reward: Risking $40 to make $60 = 1.5:1 ratio. Not good enough under the 7% rule. You pass.

Later, the same market has more information. YES is now $0.25. If YES wins, you make $0.75. If NO wins, you lose $0.25.

Risk-reward: Risking $0.25 to make $0.75 = 3:1 ratio. Better, but still under 7:1. You wait longer.

Eventually, YES trades at $0.10. If YES wins, you make $0.90. If NO wins, you lose $0.10.

Risk-reward: Risking $0.10 to make $0.90 = 9:1 ratio. Now you're interested. The potential reward vastly outweighs the risk.

Why 7:1? It accounts for realistic win rates. If you're right 50% of the time and your 7:1 rewards are true, you net +4.5% per trade (50% × +7 - 50% × -1 = 3 - 0.5 = 2.5 per unit risked). But real traders are wrong more than 50% on individu