Position Sizing
Position sizing is the most important skill in trading. Not entry timing. Not chart reading. Not setup selection. How much you risk per trade determines whether you survive long enough to develop an edge — or blow up first.
The 1% Rule
Risk no more than 1% of your account on any single trade. On a $10,000 account that's $100. On $25,000 that's $250. This is your maximum loss if the trade hits the stop. It is not the amount you invest — it's the amount you're willing to lose.
At 1% risk per trade, you can lose 20 consecutive trades and still have 82% of your account. At 10% risk per trade, 20 losses = account at $12 (starting from $10,000). The math is that stark.
The Position Sizing Formula
Step 1: Account value × risk % = dollar risk. ($10,000 × 1% = $100)
Step 2: Entry price – stop price = risk per share. ($7.20 entry – $6.50 stop = $0.70/share)
Step 3: Dollar risk ÷ risk per share = shares. ($100 ÷ $0.70 = 142 shares → round down to 140)
Step 4: Verify R:R. Target = $9.00. Reward per share = $9.00 – $7.20 = $1.80. R:R = $1.80 ÷ $0.70 = 2.57:1. Gate 3 passes.
The free Position Sizing Calculator at operatortrading.com/tools does this math instantly. Enter your account size, entry price, stop price, and risk percentage. It outputs exact shares, dollar risk, and 1R/2R/3R targets. Use it before every trade — the calculation is too important to do in your head.
The Stop Distance Problem
The tighter your stop, the larger your share size for the same dollar risk. The wider your stop, the smaller your share size. This creates a temptation: set a wide stop to "give the trade room," which forces a smaller position, which feels safer. But a wide stop that's hit is still a 1% loss — and a wide stop means your target must be proportionally further away to maintain 2:1 R:R.
The right stop is where the thesis is proven wrong — below the support level or below the EMA that defines the setup. Not an arbitrary percentage. Not "it feels right." The chart tells you where the stop goes. The formula tells you how many shares to buy given that stop.
Scaling into Winning Trades
Once a trade reaches 1R profit (target halfway), consider adding to the position. The standard OPERATOR approach: enter full position at the setup, add 50% at 1R if the setup is confirmed, trail the stop to breakeven on the original entry. This lets winners run without increasing your initial risk.