All of us, at some point, must confront our mortality. So, too, must investors prepare for the demise of a bull market that began in the depths of the financial crisis in 2009. Yes, predictions of the end of this record run have been made before—and have been proved wrong. The rally has so far seemed almost indestructible, thanks to stable economic growth and the Federal Reserve’s easy-money policy. But many market strategists and economists see powerful forces converging that could finally trip up the bull. For one, the economy has been juiced by the tax cuts and fiscal-spending package that Congress passed at the end of 2017………..