The stock market’s breadth on Wednesday was very positive because the stock market rallied, with Up Volume exceeding 85%. The stock market’s breadth on Thursday was negative because the stock market fell, with Up Volume below 30%. In other words, this was a very quick reversal in breadth. Historically, this was a bullish sign for the stock market on a 1 week - 1 month forward basis https://bullmarkets.co/study-reverse/