In recent weeks, speculators have been pressing their bets that certain publicly-traded mortgage companies could be in for a world of hurt because origination volumes are likely to remain subdued this year and there is little chance of growth through servicing acquisitions. According to figures compiled by Compass Point Research & Trading and public websites, the two most-shorted mortgage stocks are Nationstar Mortgage and PHH Corp. Measured by the percentage of shares publicly available (known as “float”), Nationstar has...