Risk reward and stop distance: the concept
Risk reward and stop distance are planning inputs that connect a position’s exit levels to the expected balance between potential loss and potential gain.
- Stop distance usually means the distance between an entry price and a stop-loss level.
- Risk reward typically expresses how the potential reward (from entry to a target) compares to the potential risk (from entry to the stop).
A key point is that these are model inputs. They assume the price moves as expected and that orders behave as intended. In live trading, that assumption can fail.
How the risks show up (mechanisms)
1) Execution risk: stop distance may not be honored
Even if you define a stop-loss level, real execution may not occur exactly at that price. Common reasons include spread changes, slippage (the difference between expected and actual execution price), and rapid price gaps. If execution happens worse than modeled, the realized loss can exceed the “planned” risk implied by your stop distance.
A material failure mode is: the market moves through the stop level, and the first available fill is at a worse price. This turns an estimate into a higher-than-expected loss.
2) Market risk: changing volatility and liquidity
Risk reward calculations often rely on a static “distance” idea, but volatility is not constant. If conditions shift—wider intraday swings, thinner liquidity, or faster order flow—then the probability that the stop is reached can change.
Liquidity can also vary by time, market session, and instrument. When liquidity drops, small changes in demand can move prices more than anticipated, increasing the chance of stop-outs.
3) Cost risk: spreads, commissions, and financing can alter the ratio
Risk reward is sometimes computed without fully accounting for all costs. Costs can include trading spreads, commissions (if applicable), and overnight financing effects. If you ignore these, the “reward” and “risk” terms are overstated or understated.
Even when the stop distance is correct, costs can reduce net outcomes and make the realized payoff less favorable than the ratio suggests.
4) Counterparty and operational risk: order handling and reporting
The planning inputs require that orders are transmitted, matched, and recorded correctly. Operational issues—such as connectivity interruptions, order rejection, or delayed reporting—can lead to outcomes that do not match the intended stop level or position size.
This is a distinct risk from market movement: the environment that executes your orders can behave differently from the assumptions used to compute risk reward.
Evidence or example (with explicit assumptions)
Consider a simplified setup with clear assumptions:
- Entry price: 1.1000
- Stop-loss level: 1.0950 (stop distance = 0.0050)
- Target level: 1.1100
- Assumption A: executions occur exactly at the defined prices.
Under Assumption A, the potential reward is 0.0100 and potential risk is 0.0050, giving a risk reward of 2:1.
Now relax Assumption A:
- Assumption B: on stop execution, slippage causes the fill to occur at 1.0940 instead of 1.0950.
- Potential risk becomes 0.0060 rather than 0.0050, making the realized risk higher than the planned “risk” term.
Also consider a cost-adjusted scenario:
- Assumption C: spreads and/or financing reduce the effective net gain and loss.
With Assumption B and C, the ratio derived from pure price distances no longer matches what you actually experience.
Limitations and key risks to verify
Limitation 1: historical relationships don’t guarantee future behavior
A ratio computed from distances does not establish that future price paths will respect those levels. Price behavior can change with volatility regimes, liquidity conditions, and macro events.
Limitation 2: interpretation risk from hidden assumptions
Risk reward may look precise, but the underlying assumptions (exact fills, stable costs, consistent volatility) might be implicit rather than explicit. Interpretation risk occurs when these assumptions are not stated, tested, or stress-tested.
Limitation 3: verification risk (what you can check)
To independently verify the relevant facts, you can compare:
- Order execution behavior (whether stop orders fill at expected levels or show slippage patterns).
- Cost components used in your calculations versus what is actually charged or realized.
- How positions and stops are reported by the trading interface or records.