Attention is the first filter, and it is rarely designed. A ticker appears in your feed, so it becomes a candidate. A scanner sorted by percentage gain shows you the most extended names in the market, and those become your day.
The bias compounds with emotion. After a loss in one instrument, that instrument occupies disproportionate attention for days, which is how one bad trade becomes a bad week.
Treat your inputs as part of the strategy. A fixed, deliberately chosen universe and a scanner tuned to your setup rather than to excitement removes most of the distortion before you make a single decision.
Related: availability-heuristic, fomo, screen-hypnosis, echo-chamber