Position sizing is the process of calculating exactly how many shares or lots to trade based on your risk tolerance and stop loss placement. It is the single most mechanical and learnable skill in risk management — yet most retail traders ignore it completely and simply buy round numbers of shares.
The 1% Risk Rule — The Standard
Risk no more than 1% of your total capital on any single trade. This limits damage from any individual loss to an amount you can recover from easily.
Position Sizing Formula
Risk Amount = Total Capital × Risk %
Stop Distance = Entry Price − Stop Loss Price
Shares = Risk Amount ÷ Stop Distance
Example:
Capital = ₹5,00,000 | Risk % = 1% | Risk Amount = ₹5,000
Entry = ₹2,000 | Stop Loss = ₹1,950 | Stop Distance = ₹50
Shares = ₹5,000 ÷ ₹50 = 100 shares (Position Value = ₹2,00,000)
Position Sizing Across Different Risk Levels
| Capital | Risk % | Risk Amount | Stop = ₹50 | Stop = ₹100 | Stop = ₹200 |
|---|---|---|---|---|---|
| ₹1,00,000 | 1% | ₹1,000 | 20 shares | 10 shares | 5 shares |
| ₹5,00,000 | 1% | ₹5,000 | 100 shares | 50 shares | 25 shares |
| ₹10,00,000 | 1% | ₹10,000 | 200 shares | 100 shares | 50 shares |
| ₹50,00,000 | 0.5% | ₹25,000 | 500 shares | 250 shares | 125 shares |
Position Sizing for NSE F&O
NIFTY Futures Position Sizing:
1 lot NIFTY = 50 units | NIFTY at 23,000 → 1 lot = ₹11,50,000 notional
Stop loss = 100 NIFTY points = ₹5,000 risk per lot
Capital ₹5,00,000 | 1% risk = ₹5,000 → 1 lot maximum
Capital ₹5,00,000 | 2% risk = ₹10,000 → 2 lots maximum
Options Buying:
Risk amount = Premium paid (you can lose 100% of premium)
Maximum spend per trade = 1–2% of capital on premium
Never spend more than ₹5,000 premium if capital is ₹5,00,000
1 lot NIFTY = 50 units | NIFTY at 23,000 → 1 lot = ₹11,50,000 notional
Stop loss = 100 NIFTY points = ₹5,000 risk per lot
Capital ₹5,00,000 | 1% risk = ₹5,000 → 1 lot maximum
Capital ₹5,00,000 | 2% risk = ₹10,000 → 2 lots maximum
Options Buying:
Risk amount = Premium paid (you can lose 100% of premium)
Maximum spend per trade = 1–2% of capital on premium
Never spend more than ₹5,000 premium if capital is ₹5,00,000
Adjusting Position Size for Volatility
A fixed position size does not account for the fact that some stocks are more volatile than others. A ₹50 stop on a ₹500 stock (10%) is very different from a ₹50 stop on a ₹5,000 stock (1%). Use ATR-based sizing:
ATR-Based Position Sizing
Stop Distance = 2 × ATR(14) of the stock
Shares = Risk Amount ÷ Stop Distance
Example — Volatile stock:
Stock price ₹1,000 | ATR = ₹40 | Stop = 2×40 = ₹80
Risk Amount ₹5,000 → Shares = 5,000 ÷ 80 = 62 shares
Example — Less volatile stock:
Stock price ₹1,000 | ATR = ₹15 | Stop = 2×15 = ₹30
Risk Amount ₹5,000 → Shares = 5,000 ÷ 30 = 166 shares
Common Position Sizing Mistakes
| Mistake | Why It Is Dangerous |
|---|---|
| Equal rupee amounts (e.g., always ₹1 lakh per trade) | Ignores stop distance — different effective risk on every trade |
| Equal number of shares (e.g., always 100 shares) | Risk varies wildly with stock price and volatility |
| Increasing size after wins (overconfidence) | One big loss wipes out multiple small gains |
| Increasing size after losses (revenge trading) | Turns a bad day into an account-threatening event |
| Not sizing down during drawdowns | Compounds losses when strategy is underperforming |
The Anti-Martingale Approach: Reduce position size during losing streaks, not increase it. If you have lost 3 trades in a row, trade 50% of normal size until you return to breakeven. Your judgment and execution are likely impaired during losing streaks — smaller size limits the damage while you reset psychologically.