Answer by Laurent Bernut:
This is answer to a question on Quora.com
This is a novice question that lead to two unprofitable biases: fairness bias and confirmation bias
When new to the fascinating short world, we want to short overvalued stocks. They believe that this has gone too far and that it “should” go down (same grammatical “should” as there “should” be peace on earth BTW).
We are hard wired for fairness. Even before speaking toddlers understand fairness. One of the subconscious beliefs behind this reversion to the mean is fairness.
Well, life is unfair, markets are unfair, let’s just get used to it. Overvalued stuff often becomes ridiculously overvalued. Remember this please: pioneers are the ones with arrows in their backs
2nd stage, when we have lost enough money playing vigilante, we often turn ultraconsetvative. We want every box to be ticked, every fact confirmed. Every bit of information has a price tag in the markets. So stocks drop like stone, waiting for confirmation is an expensive habits.
If you want to be consistently profitable in the short selling world, change your mindset from outcome (need to be right bias) to process (probabilities). Probabilities are calculated risk assuming <50% hit ratio.
Short selling is a psychological & probabilistic game