Position Sizing: How Much Should You Risk on Each Trade?

Most traders who use a fixed rule risk a small percentage of their account on each trade, commonly between 0.5% and 2%, and many beginners start at 1% or less. Your position size then comes from a simple formula: position size = (account × risk %) ÷ (entry price − stop price). The stop comes first, the size follows from it, and the amount you lose if the stop is hit stays roughly the same on every trade.

This article explains the formula, walks through worked examples for stocks, crypto and forex, and shows why small losses matter so much. It is education, not financial advice. No sizing method makes trading safe or profitable. It limits how much each mistake costs, but trading still carries a real risk of losing money, including more than you planned if prices gap or move very fast.

What position sizing actually controls

Position sizing answers one question: how many shares, coins or units should I buy or sell on this trade? It sounds like a detail, but it is the part of trading you control most directly. You cannot control whether a trade works. You can control how much it costs you when it does not.

Two traders can take the exact same trade, with the same entry and the same stop, and have completely different outcomes. One risks 1% of the account and shrugs off the loss. The other risks 20% and is badly damaged. The chart was identical. The size was not.

Good sizing has three goals:

• Survive losing streaks. Every approach has runs of losses. Small, consistent risk keeps a streak from becoming a disaster.
• Make results comparable. When each trade risks a similar amount, you can judge your decisions rather than your luck with size.
• Remove guesswork. A formula replaces the urge to go big on trades that feel good and small on trades that feel scary.

Choosing a risk percentage

Risk per trade is the amount you would lose if your stop is hit, expressed as a percentage of your account. It is not the size of the position. A $5,000 position with a stop 2% below the entry risks about $100, not $5,000.

Common ranges look like this:

• 0.25% to 0.5%: very conservative. Useful while learning, when testing a new approach, or when trading very volatile markets.
• 1%: a widely used starting point. Ten losses in a row costs about 9.6% of the account.
• 2%: often quoted as an upper limit for a single trade. Ten losses in a row costs about 18.3%.
• 5% or more: aggressive. Ten losses in a row costs about 40.1%, which is very hard to recover from.

Those streak figures assume you recalculate the risk from the shrinking balance after each loss (1% of whatever is left), which is how most traders apply the rule. For example, 0.99 multiplied by itself ten times is about 0.904, so the account falls about 9.6%.

There is no universally correct number. Consider how often your approach loses, how volatile the market is, whether you hold several correlated positions at once, and honestly, how you react emotionally to losses. If a loss would make you break your own rules, the risk is too high.

The position sizing formula

The formula has three inputs: your account size, your risk percentage and the distance from entry to stop.

1. Dollar risk = account balance × risk percentage.
2. Risk per unit = entry price − stop price (use the absolute value, so it works for short trades too).
3. Position size = dollar risk ÷ risk per unit.

Notice what is missing: the position value. You do not start by deciding to put $2,000 into a trade. You start by deciding where the trade is wrong (the stop), and the size falls out of the math. A wide stop gives a small position. A tight stop gives a larger one. In both cases the dollar risk is the same.

The stop should come from the chart, not from the size you want. Placing the stop at a level that actually invalidates your idea, then sizing to fit, is the core habit. If you are still learning to read price structure, our guide on how to read candlestick charts is a good place to start.

Worked examples

Example 1: a stock trade

You have a $10,000 account and risk 1% per trade. You want to buy a stock at $50 with a stop at $47.

• Dollar risk: $10,000 × 1% = $100.
• Risk per share: $50 − $47 = $3.
• Position size: $100 ÷ $3 = 33.33, rounded down to 33 shares.
• Actual risk: 33 × $3 = $99.
• Position value: 33 × $50 = $1,650.

Always round down, not up, so you never risk more than your limit. Notice that the trade only uses $1,650 of a $10,000 account, yet a stop-out costs about 1% of the account. That is the point: capital used and capital at risk are different things.

If you had chosen 2% instead, dollar risk would be $200, and $200 ÷ $3 = 66.67, so 66 shares, risking $198 with a position value of $3,300.

Example 2: a crypto trade

You have a $5,000 account and risk 1%. You want to buy Bitcoin at $60,000 with a stop at $57,000.

• Dollar risk: $5,000 × 1% = $50.
• Risk per coin: $60,000 − $57,000 = $3,000.
• Position size: $50 ÷ $3,000 = 0.016667 BTC. Rounding down to the exchange's step size, say 0.0166 BTC.
• Actual risk: 0.0166 × $3,000 = $49.80.
• Position value: 0.0166 × $60,000 = $996.

Crypto lets you buy fractions, which makes precise sizing easy. The catch is volatility: a stop 5% away is often tight for Bitcoin, and much tighter still for smaller coins. Wider stops mean smaller positions, which is exactly how the formula protects you. Remember to include trading fees and the bid-ask spread in your planning, since both add to the real cost of a stop-out.

Example 3: a forex trade

Forex sizing uses pips and lots, so it needs one extra step. A pip is the standard unit of price movement: 0.0001 for most pairs, and 0.01 for pairs quoted in Japanese yen. Positions are measured in lots:

• Standard lot: 100,000 units of the base currency. For pairs quoted in US dollars (such as EUR/USD), one pip is worth $10.
• Mini lot: 10,000 units. One pip is worth $1.
• Micro lot: 1,000 units. One pip is worth $0.10.

Now the trade. You have an $8,000 account and risk 1%. You want to buy EUR/USD at 1.0850 with a stop at 1.0810.

• Dollar risk: $8,000 × 1% = $80.
• Stop distance: 1.0850 − 1.0810 = 0.0040 = 40 pips.
• Risk per standard lot: 40 pips × $10 = $400.
• Position size: $80 ÷ $400 = 0.2 lots (20,000 units, or two mini lots).
• Check: 0.2 lots makes each pip worth $2, and 40 × $2 = $80.

When the quote currency is not your account currency, pip value changes with the exchange rate. For USD/JPY, one pip on a standard lot is 0.01 × 100,000 = 1,000 yen. At a rate of 150.00, that is 1,000 ÷ 150 = about $6.67 per pip, not $10. Most trading platforms calculate this for you, but it is worth understanding so you can check them. If you are deciding between markets, our comparison of crypto vs forex trading covers how their costs and volatility differ.

When the formula gives a size you cannot afford

Very tight stops can produce positions larger than your account. With a $10,000 account, 1% risk and a stop only $0.20 below a $50 entry, the formula says $100 ÷ $0.20 = 500 shares, worth $25,000. Without leverage, you cannot buy that. In that case, cap the position at what you can afford and accept a smaller risk, or ask whether a stop that tight is realistic. Tight stops are more likely to be hit by ordinary noise.

Leverage: it magnifies, it does not change the math

Leverage lets you control a position larger than the cash you put up. The cash set aside is called margin. Leverage is common in forex and crypto derivatives, and it is often misunderstood.

Go back to the forex example. A 0.2 lot position in EUR/USD is 20,000 euros, worth about 20,000 × 1.0850 = $21,700. With 1:30 leverage, the margin required is $21,700 ÷ 30 = about $723. With 1:100 leverage, it is $217. In both cases, if the stop is hit, you lose $80. The risk comes from position size and stop distance, not from how much margin the broker holds.

So why is leverage dangerous? Because it removes the natural limit on size. With $8,000 and 1:30 leverage, you could control up to $240,000. A 1% move against a position that size is $2,400, or 30% of the account, from a move that happens routinely in many markets. Traders who size from the margin available rather than from the stop are the ones who get wiped out.

Why small losses matter: the drawdown recovery table

A drawdown is the fall from an account's peak to its low point. Losses and gains are not symmetrical: after a loss, you have less capital, so you need a larger percentage gain just to get back to where you started. The required gain is 1 ÷ (1 − loss) − 1.

• −5% needs +5.3% to recover.
• −10% needs +11.1%.
• −20% needs +25%.
• −25% needs +33.3%.
• −30% needs +42.9%.
• −40% needs +66.7%.
• −50% needs +100%.
• −60% needs +150%.
• −75% needs +300%.
• −90% needs +900%.

Small drawdowns are an inconvenience. Large ones can be close to permanent. This is the strongest argument for modest risk per trade: at 1% per trade, a painful ten-loss streak leaves you down about 10%, which needs about an 11% gain to recover. At 5% per trade, the same streak leaves you down about 40%, which needs roughly a 67% gain.

Other things that affect position size

• Correlated positions. Three trades in three crypto coins that tend to move together can behave like one large trade. Consider your total risk across related positions, not just each one alone.
• Costs. Commissions, fees, spreads and funding charges all add to the cost of a losing trade. Some traders subtract expected costs from their dollar risk before sizing.
• Order type. A market order fills immediately at the best available price, which may differ from the price you planned. See market vs limit orders for how that affects your real entry.
• Volatility changes. When a market becomes more volatile, a sensible stop usually gets wider, so the position gets smaller automatically.
• Account currency. If your account is in one currency and you trade assets priced in another, exchange rates affect both your pip values and your results.

Common mistakes

• Choosing the size first and the stop second. This leads to stops placed wherever the loss feels tolerable rather than where the idea is actually wrong.
• Confusing position value with risk. Buying $1,000 of something is not the same as risking $1,000. Risk depends on the stop.
• Sizing from available leverage. Just because a broker allows 1:100 does not mean your position should be anywhere near that.
• Increasing size after losses to win it back. This is how small drawdowns become large ones.
• Rounding up. Always round the position down so the actual risk stays at or below your limit.
• Ignoring gaps and slippage. Your planned risk is a best case. Real losses can be larger.
• Forgetting fees and spreads. On short-term trades with tight stops, costs can be a meaningful share of the risk.
• Moving the stop further away after entry. This silently increases the risk you sized for.

Key takeaways

• Decide your stop first, then calculate size: (account × risk %) ÷ (entry − stop).
• Many traders risk 0.5% to 2% per trade; 1% or less is a common starting point.
• In forex, convert the stop distance to pips and use the pip value per lot.
• Leverage does not change how much you lose at the stop, but it makes oversized positions easy to open.
• Losses need larger gains to recover: −50% needs +100%.
• Sizing limits damage but does not remove risk. Trading can and does lose money.