A clean quantitative framing is this: position sizing usually matters more than entry timing for long-run performance. Desk note: A well-timed entry at too large a size can destroy a portfolio. A mediocre entry at appropriate size survives and lets the thesis work. Why investors care: That is why professional risk management starts with "how much" before "what" or "when." $$ Max\ Position = \frac{Portfolio\ Risk\ Budget}{Expected\ Position\ Volatility} $$ Plain English: Size should be set by how much risk the portfolio can absorb, not by how confident you feel. Translate it into behavior: Sizing a single stock position at 25% of the portfolio turns any -20% stock decline into a -5% portfolio hit. At 5%, the same decline costs only -1%. Where people usually get tripped up: The mistake is perfecting the entry signal while ignoring whether the position size allows recovery from being wrong. Keep this nearby on the next review: Ask whether the market is mispricing the mechanism or simply narrating it loudly. That is the kind of small conceptual habit that compounds into better decisions over time.