Position Sizing Explained: How Much to Risk Per Trade

Position sizing is how much of your account is exposed on one trade. It is the least exciting decision in trading and the one that most often decides whether an account survives. Traders spend hours on entries and almost none on size, then wonder why a few bad trades did so much damage. The size was the damage.

The useful question is not "how much can I make on this?" It is "how much do I lose if I am wrong, and can I keep trading after?" Answer that and the size follows. Sizing is one of the three levers in trading risk management; this guide covers how it works, how the stop sets it, and the rules that keep one trade from taking too much.

What Position Sizing Actually Means

Position sizing is the amount of capital committed to a single position, measured by what it costs you if the trade hits your exit. It is not "how much do I want to buy." It is "how much am I willing to lose here."

It is also not leverage. Leverage is how much exposure a given amount of margin controls. Sizing is how much of the account is at risk. You can trade with no leverage and still oversize by putting most of the account into one position. You can trade with leverage and still size small by risking a fraction of the account. On margin and perpetual products, leverage can produce a loss larger than the margin you posted, which makes disciplined sizing more important, not less.

Keeping the two ideas separate is the first step. Sizing answers "how much is at risk"; leverage answers "how is that exposure funded."

How Stop Distance Decides Your Size

The cleanest way to size is to fix the risk first and let the trade set the size. Pick the amount you are willing to lose on the trade, decide where your stop goes, and the distance between entry and stop tells you how large the position can be.

The relationship is simple: risk amount divided by the distance to the stop equals the position size. A wider stop means a smaller position for the same risk. A tighter stop means a larger one. The stop is not something you add after choosing size; it is what determines size.

The numbers above are illustration to show the mechanics, not recommended settings. What matters is the shape: hold the risk constant, and the size shrinks as the stop widens. This is why "just set a tighter stop so I can buy more" is backwards — a stop should sit where the idea is proven wrong, and the size adjusts to it.

Fixed Percent vs Fixed Amount

Two common ways to set the risk-per-trade number:

• Fixed percentage: risk a set share of the current account on each trade. As the account grows, the dollar risk grows; as it shrinks, the risk shrinks with it. This slows losses during a bad streak and compounds gently during a good one.
• Fixed amount: risk the same dollar figure every trade regardless of account size. Simpler to track, but it does not shrink your risk automatically when the account is falling.

Neither is "best." Fixed percentage adapts to the account and is common for that reason; fixed amount is easier to reason about. What matters is that the number is decided in advance and applied the same way each time, not chosen by how confident a particular trade feels.

Sizing Across Different Assets

The same 1% risk means different position sizes in different markets, because volatility differs. A crypto token that routinely moves 8% in a day needs a wider stop, and therefore a smaller position, than a currency pair that moves under 1%. Gold, forex, and crypto all behave differently, so a size that is careful in one can be reckless in another.

This is why sizing is a per-trade calculation, not a fixed lot you reuse. The method is the same everywhere — fix the risk, let the stop set the size — but the output changes with the asset. For how this plays out in a specific market, see gold risk management.

Risk Control: Sizing Rules That Protect the Account

Sizing one trade well is not enough if the account as a whole is over-exposed. A few rules keep the levers honest:

1. Cap risk per trade. Decide the maximum you will lose on any single position and never exceed it because a trade "looks certain."
2. Cap total open risk. Ten positions at 1% each in correlated markets is not 1% risk — it can behave like one large position. Watch the sum, not just each trade.
3. Account for correlation. Assets that move together should be treated as closer to one bet than several.
4. Do not average down past your plan. Adding to a loser to lower the average increases size exactly when the idea is failing.
5. Respect leverage. On margin or perpetuals, a position can be liquidated before your mental stop if the market moves fast. Size so that a normal adverse move does not threaten the account.

None of this prevents losses. It keeps a single loss, or a cluster of correlated ones, from becoming a hole that is hard to recover from. That recovery math is the subject of drawdown, and it is why sizing and drawdown are really one topic.

How to Apply This on Bifu

Bifu provides trading across crypto, forex, and commodities through /trade. Before placing an order, the useful sequence is: decide the risk you accept on the trade, choose where the stop belongs, and let those two set the size. Then place the position small enough that being wrong is survivable.

If you have watched other traders through copy trading, the same logic applies to how much you allocate to a copied strategy — see copy trading risk controls. The tool executes the order; the sizing decision stays with you.

FAQ

What is position sizing in trading?

Position sizing is how much of your account you put at risk on a single trade, measured by what you lose if the price reaches your stop. It is the main lever for surviving losing streaks.

How do I calculate position size from a stop-loss?

Divide the amount you are willing to risk by the distance from your entry to your stop. A wider stop produces a smaller position for the same risk; a tighter stop produces a larger one. The stop determines the size, not the other way around.

Is position sizing the same as leverage?

No. Position sizing is how much of the account is at risk. Leverage is how much exposure a given margin controls. You can oversize with no leverage, or size conservatively while using it. On leveraged products, careful sizing matters more because losses can exceed the margin posted.

What percentage of my account should I risk per trade?

There is no universally correct figure, and any number here is illustration rather than advice. Many traders risk a small fixed percentage so a string of losses does not end their ability to trade. The right level depends on your loss tolerance and how volatile the market is.

Conclusion

Sizing is the quiet decision that outweighs the entry. Fix the risk you accept, let the stop set the size, keep total exposure in check, and apply the same rules after a loss as before one. Do that and no single trade can end the account, which is the whole point.

Decide your risk before your next entry, and when you are ready to place a trade, review the risks and size it with a plan on Bifu.

References

• Bifu Trade
• FINRA: Crypto Assets