Most traders are well aware that fear and greed distort decisions. A quieter problem gets less attention: tiredness. After hours of watching charts, reading headlines and making small choices, the quality of judgement drops. Researchers call the general idea decision fatigue, and while the exact size of the effect is debated in the academic literature, most experienced traders recognise the pattern from their own results: more mistakes, looser rules, and impulsive entries late in a long session.
What it looks like in practice
- Rule-bending. A trade that does not quite meet your criteria starts to look “close enough”.
- Default decisions. You stop evaluating and start taking the easiest option: closing early to end the discomfort, or skipping the stop adjustment you had planned.
- Chasing. After a missed move you jump in late, which links to FOMO.
- Size creep. Position sizing, which needs a careful calculation, gets eyeballed instead (see position sizing).
- Revenge trades. Fatigue lowers tolerance for a losing run, feeding the cycle described in losing streaks and revenge trading.
Weeks with a heavy event calendar, such as several central bank decisions in a row, make this worse, because there are more headlines and more reasons to second-guess a plan.
Reduce the number of decisions you make
The best remedy is not willpower but design. Every decision you make in advance is one you will not need to make while tired.
- Use a pre-trade checklist. A fixed list of conditions turns a judgement call into a yes/no check. See our pre-trade checklist.
- Limit your instruments. Watching three pairs well is easier than watching fifteen badly.
- Set trading hours. Choose a window, such as the first two hours after the London open, and stop when it ends.
- Cap trades per day. A hard limit protects you from the late-session sequence of low-quality entries. This ties into overtrading.
- Pre-set orders. Place stop and target orders at entry rather than deciding later under pressure.
- Take real breaks. Step away from the screen, eat, and move. Even a short walk before a major release can help.
The weekly review
A daily journal captures individual trades. A weekly review steps back to look for patterns, and it is where fatigue shows up in the data. Choose a fixed time, for example Saturday or Sunday, when markets are closed and you are rested. Allow 30 to 45 minutes.
Step 1: The numbers
Count the trades, wins, losses, average win, average loss, and net result in R-multiples (profit divided by the amount risked). R-multiples let you compare trades of different sizes. Compare with your recent averages. Our article on win rate, risk-reward and expectancy explains why average win and loss matter as much as win rate.
Step 2: Timestamps
For each trade, note the time of entry and how many hours you had been at the screen. Then sort your results by time of day. If your losses cluster in the last hour of your sessions, you have found a concrete, fixable issue, and it came from your own data rather than a theory.
Step 3: Rule adherence
Mark each trade as “followed plan” or “broke plan”, and note which rule was broken. A plan-following loss is part of the business. A plan-breaking win is a warning, because it reinforces the habit. Review the trading plan template if your rules are not written down yet.
Step 4: Emotional and physical state
Add a one-line note: sleep, stress, distractions. It sounds soft, but after ten weeks you will have evidence about what conditions produce your best and worst decisions.
Step 5: One change
Choose a single adjustment for next week, such as ending sessions two hours earlier or capping trades at three a day. Changing five things at once means you will not know what worked.
An illustrative example
Imagine a trader reviewing 20 trades. Fourteen were taken in the first two hours, with an average of +0.3R. Six were taken after four hours at the screen, with an average of −0.8R. The overall result looks mediocre, but the split shows that the system is not the problem; the late-session behaviour is. The fix is a cutoff, not a new strategy. (These numbers are made up for illustration.)
Keep it kind and practical
The review is not for self-criticism. The goal is information. If a week went badly, the useful question is what you can set up differently, not what is wrong with you. Combine this with the habits in building a journal that improves results, and over time the data will tell you when you are fit to trade and when the best decision is to close the platform.
Decision fatigue is unglamorous, but guarding against it is one of the cheapest ways to improve consistency. You do not need a better indicator. You need fewer, better-rested decisions.
General education, not financial or medical advice. Examples are illustrative.