In our earlier guides, Investing for Beginners and Fundamental Analysis for Beginners, we looked at what to buy. This guide is about a question many beginners skip: how much should you put on the line, and when should you get out?
Experienced traders often say that you cannot control whether a trade wins, but you can control how much it costs you when it loses. That is what risk management is about.
Why losses matter more than gains
A loss and a gain of the same size do not cancel out. After a loss, you need a bigger percentage gain just to get back to where you started.
| Loss | Gain needed to recover |
|---|---|
| −10% | +11.1% |
| −20% | +25% |
| −30% | +42.9% |
| −50% | +100% |
| −75% | +300% |
A 50% loss needs a 100% gain to break even. That is why protecting your account usually comes before chasing big returns.
The 1% rule: how much to risk per trade
A common rule of thumb is to risk no more than 1% to 2% of your account on a single trade. "Risk" here does not mean the amount you invest. It means the amount you would lose if the trade went wrong and your stop-loss was hit.
With a $10,000 account, 1% is $100. You can still buy $2,500 worth of stock, as long as the distance to your stop-loss keeps the possible loss at about $100.
Small risk per trade protects you from losing streaks, which happen to everyone. Here is what 10 losses in a row would do to an account:
| Risk per trade | Account after 10 losses in a row |
|---|---|
| 1% | −9.6% |
| 2% | −18.3% |
| 5% | −40.1% |
| 10% | −65.1% |
At 1%, a bad streak is a setback. At 10%, it can end your trading.
What is a stop-loss?
A stop-loss is a price at which you plan to exit if the trade moves against you. Many brokers let you place it as a stop order: when the price reaches your stop price, the order becomes a market order and is sent for execution.
There are three common ways people choose where to place a stop:
- Chart structure: just below a recent low or support level for a long trade. If the price breaks that level, the reason for the trade may no longer hold.
- Volatility: a multiple of the stock's typical daily move, often measured with the ATR (average true range). A stock that moves 4% a day needs more room than one that moves 1%.
- A fixed percentage: for example 5% or 8% below the entry. It is simple, but it ignores how the stock actually behaves.
An important limit: a stop price is not a guaranteed price. If a stock gaps down overnight, for example after an earnings report, it can open far below your stop, and the order will be filled at the next available price. The SEC's investor education office and FINRA both warn about this in their guides to stop orders.
Position size: how many shares to buy
Once you know your risk amount and your stop-loss, the number of shares follows from a simple formula:
Shares = Amount you are willing to lose ÷ (Entry price − Stop-loss price)
Example:
- Account: $10,000
- Risk per trade: 1% = $100
- Entry price: $50
- Stop-loss: $48, so the risk per share is $2
- Shares: $100 ÷ $2 = 50 shares
- Position value: 50 × $50 = $2,500
If the stop is hit, you lose about $100, or 1% of your account, even though you invested $2,500.
Two details change the result in real life:
- Commissions: with a $1 fee to buy and another $1 to sell, the same budget allows 49 shares, not 50.
- Fractional shares: with a small account, whole shares may not fit your risk budget. Some brokers let you buy parts of a share.
Our free Position Size Calculator does this math for you, including commissions (a fixed fee, a percentage or per share) and fractional shares. No sign-up is needed.
Risk/reward ratio: is the trade worth it?
The risk/reward ratio compares what you could lose with what you could gain.
In the example above, with a take-profit target at $56:
- Risk: $50 − $48 = $2 per share
- Reward: $56 − $50 = $6 per share
- Risk/reward: 1:3
The ratio also tells you how often you need to be right just to break even, before costs:
| Risk/reward | Win rate needed to break even |
|---|---|
| 1:1 | 50% |
| 1:2 | 33.3% |
| 1:3 | 25% |
With a 1:3 ratio, you could be wrong three times out of four and still roughly break even. A high ratio is not a guarantee, though. A target that is far away is also less likely to be reached.
Try different entries, stops and targets in the free Risk/Reward Calculator.
Common risk management mistakes
- Moving the stop-loss further away when the price gets close to it. This turns a planned small loss into an unplanned large one.
- Averaging down without a plan. Buying more as the price falls lowers your average price, but it also increases how much you have at stake. If you do it, decide the total amount in advance. The Average Down Calculator shows your new average and the money involved.
- Making positions too big. A single trade should not be able to seriously damage your account.
- Ignoring earnings dates. Prices can jump or fall sharply after an earnings report, and a stop may not protect you from a gap. On L.WIN, stocks on your watchlist with earnings in the next 7 days are flagged, so the date does not catch you by surprise.
- Holding many stocks that move together. Five tech stocks can behave like one big position when the whole sector falls.
A pre-trade checklist
Before you place an order, answer these questions:
- Why am I entering this trade?
- Where is my stop-loss, and why there?
- How much money will I lose if the stop is hit, and is it within 1% to 2% of my account?
- How many shares does that allow?
- Where is my target, and what is the risk/reward ratio?
- Is there an earnings report or other major event before my planned exit?
If you cannot answer one of them, it may be better to wait.
Keep a trading journal
Write down every trade: the entry, the stop, the target, the result and the reason you took it. After 20 or 30 trades, patterns appear, such as stops placed too tight or trades taken out of boredom. L.WIN members get a built-in journal with monthly statistics for exactly this.
Key takeaways
- A loss needs a bigger gain to recover, so protecting your account comes first.
- Risk a small, fixed part of your account per trade, often 1% to 2%.
- Decide on your stop-loss before you enter, and know that it is not a guaranteed exit price.
- Let the stop distance decide your position size, not the other way around.
- Check the risk/reward ratio and the earnings calendar before every trade.
Our technical analysis guide, which looks at support, resistance and trends, is coming next. Until then, try the free L.WIN tools on your next trade idea.
This article is for educational purposes only and is not investment advice. Always do your own research and consider your personal situation before making any investment decision.
Sources: Investor.gov (SEC): Stop, Stop-Limit, and Trailing Stop Orders · FINRA: Stop Orders, Factors to Consider During Volatile Markets