Does anyone remember when single-strategy hedge funds started branching into other strategies with a passion three years ago? The big debate back then was style drift, and whether these managers had the experience to invest in asset classes beyond their existing expertise.After a brief period of humming and hawing, investors decided it was better for a fund to have broader investment opportunities, and the hedge fund managers performance in multi-strategy funds eased any concerns about their expertise.What no one considered at that...