In the short run the market is a voting machine, In the long run it is a weighing machine
"Whether the market goes up or down a few points in any one month does not alter the fact that if extraordinary increases in earnings radically changes the value of a certain stock, the price of that stock will perhaps slowly but with certainty adjust itself to its new value (Dow, Charles H. Wall Street Journal. Review and Outlook. October 25, 1900)."