Position sizing explained

Position sizing is deciding how much to trade on any given position — and it's the mechanism that turns "risk 1% per trade" from a nice idea into an actual number of shares or contracts. It's one of the most important and least glamorous skills in trading, because it's the difference between a losing streak that's survivable and one that ends your account.

Why position sizing matters more than entries

Most beginners obsess over entries — when to buy, when to sell. But two traders can take the exact same trades and one gets rich while the other blows up, purely because of how much they put on each one. Size too large and a normal losing streak wipes you out before your edge can pay off. Size correctly and you survive the streak and profit over time. The entry determines whether a trade wins; the size determines whether you survive being wrong.

The core method: risk-based sizing

Professional position sizing works backwards from risk, not forwards from confidence. The steps:

• Decide your risk per trade — say 1% of your account.
• Find your stop distance — how far from your entry is the price where you're wrong?
• Divide — your position size is your dollar risk divided by your per-unit risk (the stop distance).

In plain terms: if you're willing to lose $100 on a trade and your stop is $1 away per share, you buy 100 shares. If the stop is $2 away, you buy 50. The size adjusts so that hitting your stop always costs the same fixed amount, regardless of the trade. This is the key insight: your position size changes with your stop distance, so your risk stays constant.

Why constant risk is the goal

When every trade risks the same small amount, no single trade can seriously hurt you, and your results become a clean test of your edge rather than a random walk driven by wildly different bet sizes. It also removes emotion from sizing: you're not putting on more because you "feel good" about a trade — feeling good is exactly when overconfidence gets you. Fixed fractional risk means the market, not your mood, is never allowed to take an outsized bite.

The mistake that kills accounts

Sizing based on confidence instead of risk. A trader feels certain, so they put on a huge position — and certainty in trading is an illusion. The trades you're most confident about are not reliably the ones that win, and betting big on conviction is how a single trade erases weeks of careful profit. The discipline is to size the same way whether you feel certain or uncertain, because your feelings aren't predictive and your sizing shouldn't pretend they are.

Sizing and account survival

Run the math and it's stark. Risk 2% per trade and even a long losing streak leaves you with most of your account. Risk 20% and five losses in a row — which happens to every strategy — nearly ends you. Position sizing is the dial that sets how much variance your account can absorb, and setting it conservatively is what keeps you in the game long enough for your edge to matter. Almost every blown account is really a position-sizing failure wearing a different mask.

How I size

I trade micro futures specifically because the small contract size makes risk controllable, and I size every position off a fixed risk per trade against a defined stop — the same way whether I feel confident or not. It's on the record: consistent sizing, session after session, because the point is never the size of any one win. It's surviving to take the next hundred trades.