Stop Loss, Take Profit and the R Multiple
A stop loss is not an opinion about where price will go. It is a pre-agreed definition of how much you are wrong by.
A stop loss is not a prediction about where the price will go. It is a pre-agreed definition of how much you are wrong by, set before the trade begins and not moved afterwards.
Once you start expressing every result as a multiple of that initial risk, position size stops distorting your judgement and you can compare trades made years apart on equal terms.
Define risk first, then derive size
Most traders do this backwards. They decide how many lots to trade, then wonder where to put the stop. The correct order is the reverse: decide how much money you are willing to lose, decide where the trade is invalidated, then calculate the size that makes those two numbers agree.
This is why the stop has to be placed at a level that means something. If you pick a stop distance because it is a round number or because it lets you trade a bigger size, the position no longer reflects your actual risk.
R as a unit of measurement
R is simply your initial risk on a trade. If you risk $100, then 1R equals $100. A trade that makes $200 is a +2R result. A trade stopped out is −1R. That is all it is.
The value is that it removes position size from your emotional response. A −1R loss on a small position and a −1R loss on a large position are the same event. You stop reacting to dollar amounts and start reacting to whether the process worked.
Reward-to-risk is meaningless alone
A 3:1 reward-to-risk ratio sounds excellent until you learn the win rate is 20%. Expectancy — average win times win rate, minus average loss times loss rate — is what actually determines profitability.
This is why fixed ratio targets can be harmful. A target chosen because it makes the ratio look good, rather than because it sits at a real level in the market, will drag your win rate down until the ratio no longer helps you.
Place stops at structure, not at convenience
A stop belongs somewhere the trade idea is genuinely invalidated: beyond a swing low, above a structural high, outside a volatility envelope. The market does not know where your account would prefer it to be.
If placing the stop at a sensible structural level makes the position too small to bother with, the correct conclusion is that the trade is not worth taking — not that the stop should move closer.
Expressing outcomes in R, with 1R equal to $100 of risk
| Outcome | Currency result | Result in R |
|---|---|---|
| Stopped out at the stop | −$100 | −1R |
| Closed at break even after fees | −$7 | ≈ 0R |
| Target hit at 2× risk | +$200 | +2R |
| Target hit at 3× risk | +$300 | +3R |
| Stop slipped during news | −$180 | −1.8R |
Key takeaways
- Set the stop where the idea is invalidated, then size the position to fit
- R is your initial risk; expressing results in R removes size from your emotions
- Reward-to-risk without a win rate tells you nothing — use expectancy
- Moving a stop further away because a trade is losing is how accounts end
- Define risk in currency first, then derive the position size from it
- R is your initial risk; expressing results in R removes position-size noise
- A fixed reward-to-risk ratio means nothing without a win rate
- Stop placement should follow market structure, not a round number
Moving a stop loss further away because the trade is currently losing.
Reading is not verification
Take the concept you just read and turn it into explicit rules, then test it. That is the only way to know whether it actually works.
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