Key takeaways
- Decide where you are wrong first; the stop distance then determines the position size.
- Risk a fixed small share of equity per trade and express results in R.
- Expectancy combines win rate and reward-to-risk; a high win rate with small wins can lose money.
- Drawdowns are asymmetric: a 50 percent loss needs a 100 percent gain.
- Correlated positions are one idea; count them together.
- Pre-set daily, weekly and monthly limits protect you when judgement is weakest.
Most traders spend their time looking for better entries and almost none designing what happens when they are wrong. Risk management is that design. It decides how big each position is, how much you can lose in a day or a month and how you behave when a plan stops working. It does not make a poor method profitable, but it keeps a sound method alive long enough to prove itself, and it stops a bad week from becoming the end of the account. This guide builds a complete system from a handful of rules and worked numbers.
The three questions every trade must answer
Before any position is opened, three numbers should exist: where you are wrong, how much you lose if you are wrong and how much you risk compared with your account. Where you are wrong is a price level, such as below a recent swing low, chosen because beyond it the idea no longer holds. How much you lose is the distance to that price times the position size. How much you risk relative to the account is that loss as a percentage of equity. If you cannot write all three before clicking, the trade is a guess.
Risk per trade and the position sizing formula
The core rule is to fix the percentage of equity you will lose if a trade hits its stop, commonly between 0.5 and 2 percent, and then derive the position size from it. The formula is risk in money divided by the stop distance in price times the value of one unit of price movement. In forex that is risk in money divided by the stop in pips times the pip value per lot, which gives the size in lots.
| Equity | Risk per trade | Risk in money | Stop (pips) | Pip value per lot | Position size |
|---|---|---|---|---|---|
| $10,000 | 1% | $100 | 20 | $10 | 0.50 lot |
| $10,000 | 1% | $100 | 50 | $10 | 0.20 lot |
| $10,000 | 0.5% | $50 | 50 | $10 | 0.10 lot |
| $2,000 | 1% | $20 | 40 | $10 | 0.05 lot |
R multiples: measuring every trade against its risk
Define 1R as the money you risk on a trade. A trade that stops out loses 1R, one that gains twice the risk makes 2R. Measuring in R strips away account size, currency and lot size, so results can be compared across trades and across markets and you can see your method rather than your luck. A sequence such as minus 1R, minus 1R, plus 3R, minus 1R, plus 2R sums to plus 2R even though three of five trades lost.
Expectancy: the average result of a method
Expectancy is the average R you make per trade: win rate times average win in R minus loss rate times average loss in R. It combines three numbers that mean little alone. A strategy that wins 40 percent of the time with an average win of 2R and an average loss of 1R has an expectancy of 0.4 times 2 minus 0.6 times 1, which is plus 0.2R per trade. A strategy that wins 70 percent of the time with an average win of 0.4R and an average loss of 1R has 0.7 times 0.4 minus 0.3 times 1, which is minus 0.02R: a high win rate that loses money.
| Method | Win rate | Average win | Average loss | Expectancy per trade |
|---|---|---|---|---|
| A: frequent small wins | 70% | 0.4R | 1R | -0.02R |
| B: rare large wins | 35% | 3R | 1R | +0.40R |
| C: balanced | 45% | 1.5R | 1R | +0.125R |
| D: coin flip with costs | 50% | 1R | 1.1R | -0.05R |
Computed as 1 divided by (1 plus the ratio), before costs.
Drawdown and the arithmetic of recovery
A drawdown is the fall from an equity peak to a later low. Its danger is arithmetic: the percentage gain needed to recover grows faster than the loss. Losing 10 percent needs 11.1 percent to recover; losing 25 percent needs 33 percent; losing 50 percent needs 100 percent. That is why a risk system aims to keep drawdowns shallow rather than to maximise each win, and why a series of oversized losses damages an account far more than a series of small ones.
| Loss from peak | Gain needed to recover | Trades to recover at +0.2R per 1% risked |
|---|---|---|
| 5% | 5.3% | about 26 |
| 10% | 11.1% | about 56 |
| 20% | 25.0% | about 125 |
| 30% | 42.9% | about 215 |
| 50% | 100.0% | about 500 |
Correlation: avoiding hidden double positions
Two positions that look separate can be the same bet. Long EUR/USD and long GBP/USD are both short the dollar; long AUD/USD and long NZD/USD move together most of the time. If you risk 1 percent on each and they are 80 percent correlated, your combined risk is roughly 1.9 percent on one idea rather than 2 percent on two. Before opening a second position, ask whether it adds a different risk or the same one. Count correlated positions together against a per-idea limit.
Daily, weekly and monthly loss limits
A per-trade limit protects against one bad trade. A loss limit over a period protects against the spiral that follows several, when judgement is worst. A common structure is a daily limit of two to three times the per-trade risk, a weekly limit of two to three times the daily limit and a monthly limit after which you stop and review. When a limit is hit you stop trading until the next period. The value of the limit is that it is decided in calm conditions and applied automatically in stressful ones.
| Limit | Example setting (10,000 account) | What happens when reached |
|---|---|---|
| Risk per trade | 1% = $100 | Position size reduced or trade skipped |
| Daily loss | 3% = $300 | No more trades today; review in the journal |
| Weekly loss | 6% = $600 | No new trades until next week; review the plan |
| Monthly drawdown | 10% = $1,000 | Pause live trading; return to demo or reduce size by half |
Stops, targets and the cost of being stopped
A stop-loss is only as useful as its placement and its reliability. Place it beyond a level that invalidates the idea, with allowance for normal volatility, for instance a multiple of the average true range. Know the order types your broker offers: a standard stop can fill beyond your price in a gap, while a guaranteed stop, where offered, fills at your level for a fee. Remember that stops are triggered by the quote that includes the spread, which widens in fast markets. Tight stops mean larger positions for the same risk and more exposure to costs.
Build your risk plan in six steps
- Choose risk per trade. Pick a percentage you can lose ten times in a row without panic, often 0.5 to 1 percent for beginners.
- Write the sizing formula in your plan. Risk in money divided by stop distance times value per pip.Tip: Use a calculator until it becomes routine.
- Set daily, weekly and monthly limits. Express them as percentages and as money.
- Define what counts as one idea. Group correlated positions and limit risk per idea.
- Decide what you do after a loss limit. A written rule, such as stopping for the day and reviewing, removes the decision in the moment.
- Review monthly in R. Compute win rate, average win, average loss and expectancy from your journal.Tip: If expectancy is negative after enough trades, change the method, not the size.
Frequently asked questions
What is a good risk per trade?
Many traders use between 0.5 and 2 percent of equity. Beginners often choose the low end. The right number is one you can lose repeatedly without changing your behaviour.
Can I risk more when I feel confident?
Confidence is not evidence. Increasing size after wins and decreasing it after losses is common and usually backwards. Change risk by rules, for example after a defined number of trades, not by feeling.
How many trades do I need to judge a method?
Small samples are noisy. Thirty trades rarely prove or disprove a method; a few hundred tell you more. Always include costs.
Should I use a fixed lot size?
A fixed lot size means the money at risk changes with the stop distance. Sizing from risk and stop keeps the loss per trade consistent.
Is a stop-loss always necessary?
For leveraged products, a defined exit is essential, whether a stop order or a rule you apply manually. Without it, you are relying on discipline in the moment you are least likely to have it.
What is a risk-reward ratio of 1:2?
You aim to gain twice what you risk. It needs a win rate above about 33 percent to break even before costs, and targets that wide are hit less often than narrower ones.
How do costs affect these numbers?
Costs add to every loss and subtract from every win, which raises the break-even win rate. They matter most when stops are tight.
What do I do after a big loss?
Stop, record what happened, check whether you followed your rules and reduce size or pause according to your plan. Do not trade to win it back.