Sleep debt and the cost of trading the Asian session after a bad night

[Fairman]

Sleep debt and the cost of trading the Asian session after a bad night

Trading while tired is similar to trading impaired. Research on sleep deprivation shows slower reaction, poorer risk assessment, and heightened emotional responses. For a scalper, whose edge depends on speed and consistency, that is directly damaging.

Traders who cover multiple sessions, such as London in the morning and Asia at night, often accumulate sleep debt without noticing. Performance slips gradually, and the cause is misattributed to market conditions.

Compare results against sleep records. Even a rough log of hours slept the night before, set against the next day's trading results, can reveal a relationship.

If the data shows that days after poor sleep have worse results, the rule is simple: reduce size or skip the session. Skipping a day after a bad night costs less than the average damage done by trading tired.

Planning the schedule around sleep rather than market hours is a strong long-term decision.

Does the trade log show a performance difference after short nights?

[Amanhasnoname]

I resisted this idea for a long time, then kept a simple sleep note in my journal for about six weeks, just hours slept and a one to five score for how rested I felt. When I sorted the trading days by that score, the pattern was embarrassing. Days after fewer than six hours of sleep were negative overall, and almost all of my biggest rule violations sat in that group.

The errors were specific. I moved stops away from price, took entries a candle late, and chased after a loss. None of these happen when I'm rested because I just follow the plan on autopilot. When I'm tired the plan takes effort, and effort is the first thing to go.

I now have a hard rule. If I slept under six hours, I trade half size for the first session only and I stop for the day after the first loss. If it was a really bad night, I skip the Asian session entirely and go back to bed. It costs me a few missed setups a month, which is nothing next to the damage I used to do.