In the NYSE there are only a few stocks that are holding up the indexes, Dow Jones Industrials Average (DJIA), the S&P 500 Index and the Nasdaq 100 Index. Ten or fifteen big cap tech stocks like Facebook (FB), Amazon (AMZN), Apple (AAPL), Google (GOOG). The assumption is that all of those stocks are going to continue to grow forever, getting bigger and bigger. Maybe some of them will but looking back at history that is rarely the case. Nothing really goes on forever.