A stop-loss is an order that closes your trade automatically if price moves against you to a level you chose in advance. A take-profit closes it automatically when price reaches your target. Set together before entry, they fix your planned loss and planned gain. Place the stop where your trade idea is proven wrong, such as just beyond a support level, rather than at a random percentage.
What the order does once price touches your level
A stop-loss is a standing instruction to exit. On a long trade it sits below the current price; on a short trade it sits above it. Nothing happens while price stays on the right side. The moment price trades at your stop level, the order triggers and, on most platforms, becomes a market order that closes the position at the next available price.
A take-profit is the mirror image. It sits above price on a long and below price on a short, and it closes the trade when your target trades. Because it only fills at your level or better, it behaves like a limit order.
Both orders are set before you need them. That is the whole point. You decide your exit while you are calm, and the order carries it out when you might not be.
Put the stop where your idea is proven wrong
Every trade rests on a reason: a bounce off support, a hammer after a selloff, a breakout above a range. The stop goes at the price where that reason no longer holds. Not at a round 5%, not at the amount you feel like losing.
Some common structure-based placements:
- Beyond a pattern low or high. If you buy after a hammer, the low of its lower wick is where buyers stepped in. If price trades back under it, the pattern failed.
- Beyond a support or resistance zone. Buying near support means the stop belongs below the zone, not inside it. Shorting under resistance means it belongs above. The guide to support and resistance covers how to draw those zones.
- Beyond the last swing. In an uptrend, that is the most recent higher low. If price breaks it, the trend you were trading has at least paused.
Then add a small buffer. Price often pokes a little past an obvious high or low before turning, and a stop placed exactly on a candle's low is where many other traders put theirs too.
The order of work matters. Find the stop first, then decide whether the trade is worth taking. If the logical stop is so far away that the risk is too large, the answer is a smaller position or no trade, never a closer stop.
Measuring the trade in R
Traders describe risk and reward in R, where 1R is the distance from your entry to your stop. It turns every trade into the same unit, whatever the market or price.
A hypothetical long:
- Entry at $100, stop at $96. Your risk is $4 per unit, so 1R = $4.
- Take-profit at $108. That is $8 of reward, or 2R.
- If the trade fails you lose 1R. If it works you gain 2R.
R also tells you how often you need to be right. At 2R targets, winning one trade in three breaks even: one win of +2R cancels two losses of 1R each. At 1R targets you need to win half your trades just to break even, and more than half once costs are counted. That is why the risk-reward ratio sits next to your win rate in any honest review of your trading.
R connects straight to position sizing. Say you have $2,000 and risk 1% per trade: that is $20. With 1R at $4 per unit, you can hold 5 units ($20 divided by $4), a $500 position. A wider stop means fewer units, not more risk.
Choosing a take-profit that the chart allows
A target should sit just before the next place price is likely to stall: the next resistance zone on a long, the next support on a short, or a prior swing high or low. Aim a little short of that level rather than exactly on it, for the same reason stops get a buffer.
Then do the arithmetic. If the nearest resistance is only 1R above your entry, the trade offers 1:1 at best, and a bit less once you aim short of it. You can accept that knowingly, or skip it. What you should not do is pretend the target is higher than the chart says it is.
Some traders take part of the position off at 1R or 2R and let the rest run with the stop moved up. That is a valid approach, but decide it before entry, including where the stop moves to. A plan written mid-trade is usually a reaction to the last few candles.
When slippage and gaps push a loss past 1R
A stop-loss caps your planned loss, not your actual one. Once triggered, it fills at whatever price is available, and in a fast market that can be worse than your level. The difference is slippage, and it grows when liquidity is thin or news hits.
Gaps are the bigger version. Markets that close overnight or on weekends, such as stocks and ETFs, can open at a very different price from where they closed. If a stock closes at $98 with your stop at $96 and opens the next morning at $93, the stop triggers at the open and fills around $93. On the example above, that is a $7 loss per unit, 1.75R instead of 1R. Crypto trades around the clock, so it does not gap in the same way, but a sharp move in a few seconds can still skip past your level.
Take-profit orders work the other way around. A gap through your target usually fills at your price or better.
Gaps and slippage matter most with borrowed money. With leverage, a move that jumps past your stop can take a much bigger bite out of your margin than you planned, and in the worst case reach liquidation before the stop is any help.
Four habits that break the R math
- Stops that are too tight. A stop inside the normal back-and-forth of the market gets hit by noise, not by the trade being wrong. Look at the size of recent candles on your timeframe. If a typical 1H candle on Bitcoin is wider than your whole stop distance, you are paying to be shaken out.
- Moving the stop further away. Price approaches your stop, you nudge it lower "to give it room", and your 1R loss becomes 2R or 3R. This one does the most damage, because it removes the only limit the trade had.
- Pulling the target in out of nerves. You planned 2R, the trade reaches 1.2R, and you grab it. Do that often and your wins shrink while your losses stay full size, so the one-in-three breakeven from the R section no longer holds.
- Using a "mental stop". A stop that exists only in your head is a suggestion. When price gets there, most people find a reason to wait.
Most of these are emotional rather than technical, which is why the page on trading psychology is worth reading alongside this one.
Drilling it with paper money first
Placing stops well is a skill you build by repetition, and the lessons are cheaper when the money is not real. In Alphacent, stop-loss and take-profit orders are part of the Pro subscription, and they execute automatically at live market prices.
You can run the same drill on the free tier by hand. Before each practice trade, write down the entry, the structure-based stop, the target and the R multiple. Close the trade yourself when either level trades, and log the result in R. After 20 trades, check two numbers: how often you hit the stop versus the target, and whether you ever moved a stop away. The second number tells you more.
Worked examples on this page use a hypothetical paper account and are for learning only, not advice. In Alphacent, free trades use a fixed $1,000 size; choosing your size, stop-loss and take-profit orders, and leverage are Pro features.
Questions people ask
What is a good stop-loss percentage?
There is no fixed number. The "1% or 2% rule" you often see quoted refers to how much of your account you risk per trade, not how far the stop sits from your entry. The stop distance comes from the chart. The position size is what you adjust so that distance costs you 1% or 2%.
What is a trailing stop-loss?
A trailing stop follows price at a set distance as the trade moves in your favor and never moves back. Trail a long by $3 and let price rise from $100 to $110, and the stop climbs to $107. It protects gains in clean trends but tends to exit early when the market chops sideways.
What is the difference between a stop-loss and a stop-limit order?
A standard stop-loss becomes a market order when triggered, so you get out but the price is not guaranteed. A stop-limit becomes a limit order, so you never fill worse than your limit, but you may not fill at all. If the market gaps past your limit, the order sits unfilled and you are still holding a losing trade.