The hot-hand fallacy is the mirror image of the gamblers-fallacy. Instead of expecting a reversal after a run, you expect the run to continue because you feel hot.
Some of this is real. A trader in rhythm with a market regime genuinely has better information than one who is fighting it. The damage comes from the size increase. Four wins in a row triggers a doubled position on the fifth, and the fifth arrives just as the regime turns. A month of grinding disappears in one trade sized by mood.
Keep the size decision mechanical. Position size should come from risk-per-trade and stop distance, not from how the last few trades went. If you want to scale with performance, scale on equity over weeks, not on a streak.
Related: gamblers-fallacy, house-money-effect