June 30, 2017   Dear Investor: In the short term, markets react to nearly everything—or to nothing at all. In the long term, only one thing matters: the growth rate of earnings, relative to interest rates and the price paid. Traders, pundits and speculators waste their time trying to predict things like political machinations, macro themes and Federal Reserve policy. These things are unknowable. The investor, by contrast, buys good...