Position Sizing and Risk per Trade

Position sizing answers the only question you fully control in trading: how much money is exposed to being wrong on this trade? The standard answer — risk 1-2% of your account per trade — is not about limiting excitement; it is arithmetic that keeps a normal losing streak from becoming an account-ending one. Sizing discipline does more for long-term survival than any entry technique, because it determines whether you are still solvent when your edge finally shows up.

Risk per trade is not position size

The first clarification matters more than any formula: the amount you risk is not the amount you spend. If you buy $2,000 of ETH with a stop-loss 5% below entry, your risk is $100 — the loss if the stop executes as planned — not $2,000. Conflating the two leads to both errors: some beginners think a $2,000 position means risking $2,000 (too timid, tiny positions with stops so wide they are meaningless), while others place no stop at all, in which case the position size really is the amount at risk.

Risk per trade = position size × distance from entry to stop. Fix the risk, and the position size follows.

The sizing formula

Three inputs give you the position size for any trade:

Account risk: the dollar amount you allow yourself to lose on one trade — commonly 1% or 2% of the account.
Entry price and stop price: where you get in, and where the trade is proven wrong.

Then:

Position size = account risk ÷ (entry − stop)

Worked example. Account: $10,000. Risk per trade: 1% = $100. You want to buy ETH at $3,200 with a stop at $3,040 — a $160 (5%) stop distance.

Position size = $100 ÷ $160 = 0.625 ETH, which is $2,000 of exposure.

Notice what the formula does automatically: a tighter stop permits a larger position for the same risk (a $80 stop distance would allow 1.25 ETH), and a wider stop forces a smaller one. Volatile coins that need wide stops therefore get small positions — the formula bakes in volatility adjustment without you having to think about it. What you must not do is run the logic backward: choosing a position size first and then dragging the stop to fit guarantees stops placed where they are convenient rather than where the trade is actually invalidated.

Why 1-2%: the arithmetic of drawdowns

The percentage is not folklore; it comes from two compounding facts about losses.

Losing streaks are normal. Even a strategy that wins 50% of the time will produce streaks: over a few hundred trades, runs of 7-10 consecutive losses are expected, not exceptional. The question is what such a streak does to your account at different risk levels. Ten straight losses at 1% risk leaves roughly 90% of the account. At 5% risk, about 60%. At 10% risk, about 35%. Only the first of those is a bruise; the others change what you can do next.

Losses are asymmetric. A 10% drawdown needs an 11% gain to recover. A 30% drawdown needs 43%. A 50% drawdown needs 100% — you must double what remains just to get back to even. The recovery requirement grows faster than the loss, which is why the practical goal of sizing is to make deep drawdowns nearly impossible rather than to maximize any single win.

Risking 1-2% means a bad month is survivable and a bad quarter is recoverable. Risking 10% means one ordinary streak ends the account. In crypto, where overnight 10-20% moves in individual coins are routine, this discipline matters more than in calmer markets, not less.

There is also a psychological dividend: at 1% risk, no single trade matters enough to panic over, which makes it far easier to honor stops and follow a plan. Oversized positions produce exactly the fear and hope that cause plan-breaking behavior.

Sizing beats picking

A counterintuitive truth: two traders can take the identical entries and exits, and one grows an account while the other destroys it, purely through sizing. The picker's fantasy — that success comes from finding the right coin — ignores that no selection process avoids losers. Since losers are guaranteed, the controlling variable is how much each loser costs. A mediocre strategy sized conservatively survives long enough to be improved; a brilliant strategy sized recklessly dies on its first normal streak. You cannot control whether the next trade wins. You fully control what it costs if it does not. Spend your discipline on the variable you control.

Portfolio-level limits

Per-trade risk is not the whole picture, because trades can lose together.

Correlation is the crypto trap. Five open positions in five different altcoins, each risking 1%, is not five independent 1% risks — most altcoins fall together when bitcoin falls, so a single market-wide drop can hit all five stops in one night, a 5% loss from one event. Treat highly correlated positions as one position for risk purposes, or cap total open risk (a common cap is 5-6% across all open trades).
Set a drawdown circuit breaker. Decide in advance that, for example, a 10% account drawdown halts new trades for a review week. Losing streaks degrade judgment exactly when stakes feel highest; a pre-committed pause rule removes the decision from the worst possible moment.
Separate trading capital from savings. Sizing rules protect the trading account; nothing protects you if the trading account keeps getting refilled from money that had another job. Fix the account size, and let its growth or shrinkage be the honest scoreboard.

Making it routine

The entire discipline compresses into a pre-trade ritual that takes under a minute: know your account size, take 1% of it, find your stop level first (where is this trade wrong?), divide risk by stop distance, and place that size — then leave the stop where the analysis put it. Traders who do this every time have converted their worst outcome from a variable into a constant. Everything else in trading remains uncertain; this part never has to be.

Key Takeaways

Risk is position size times stop distance — fix the risk first (1-2% of account) and let the formula set the size, never the reverse.
Position size = account risk ÷ (entry − stop): tighter stops allow bigger positions, volatile coins automatically get smaller ones.
Losing streaks of 7-10 trades are statistically normal; at 1% risk they are a bruise, at 10% risk they are the end of the account.
Losses are asymmetric — a 50% drawdown requires a 100% gain to recover — so sizing exists to make deep drawdowns nearly impossible.
Correlated altcoin positions are effectively one trade; cap total open risk and pre-commit a drawdown pause rule before you need it.