IStockphoto A heroic run?Barring a breathtaking plunge, the bull market in U.S. stocks on Aug. 22 will become the longest in history, and optimistic investors argue it has miles to go before it rests. The bull market has thrived amid a decade of financial and political upheaval, thanks in part to the all-you-can eat liquidity feast hosted by the Federal Reserve and other major central banks. Now the Fed has shifted to a tighter monetary policy regime even as the same risks that have dogged this market over the years, including elevated valuations, persist, prompting some pundits to predict an imminent demise of the bull.via