Statistically, after a big drop the next day has a > 50% probability of an up day.take the drop in the S&P yesterday, did anyone call the 2.3% rise today - before the fact?
I am no mathematician or statistician but in this business it pays to understand a little statistics and probability. Like playing blackjack, the card distribution is random but if you can count cards, the outcome has a slightly > 50% in your favor. You do need to play more than a few times to take advantage of the slight statistical advantage. I think trading is in general similar.