Action bias is the goalkeeper diving to one side because standing still looks lazy, even though standing still saves more penalties. Traders dive constantly. The market is quiet, no setup is present, and a position appears anyway.
It is fed by the fixed costs of the day. You paid for data, you cleared your calendar, you are sitting in the chair, so flat feels like failure. That is boredom-trading with a respectable job title.
The countermeasure is to make waiting an action with a name. Log no-trade days in your journal as correct executions. Set a minimum quality bar and record when a candidate failed it. What gets recorded stops feeling like nothing.
Related: omission-bias, overtrading, process-over-outcome