In the world of stocks, the past is a funny thing. It doesn’t really tell us much about the future. Yet most investors, market professionals and amateurs alike operate as if it does. If the pace of stocks’ growth were predictable, as the widespread study of market trends and past performance assumes it to be, one might reasonably conclude that the S&P 500 today should be 95% higher than it currently is, based on a trend line that begins with the index’s 1932 low and is drawn through its March 2000 high. Such a line suggests...

Source: Wall Street Journal December 10, 2018 03:16 UTC