A federal appeals court upheld a ruling that barred hedge funds from suing to overturn the U.S. government’s 2012 decision to capture billions of dollars in the profits generated by the mortgage guarantors Fannie Mae and Freddie Mac after their bailout, sending shares plunging. Some Fannie Mae and Freddie Mac investors still have a shot at money damages, based on when they acquired their shares and whether they did so before or after the Federal Housing Finance Agency was created and then imposed its control over Fannie Mae and Freddie Mac.