Harvard Business School professor Michael Porter has influenced generations of MBAs and world-famous value investors. But could his investing ideas be wrong? Value investing used to be about betting on the underdog — finding the down-and-out losers and gambling that they might have one more fight left in them. Today’s value investors have a new gospel: Harvard Business School professor Michael Porter’s Competitive Strategy. Porter’s theory is that power leads to profits. The wider the moat, the greater the market share, the greater a company’s ability to squeeze profits from competitors, suppliers, and customers.