Hedge fund manager Pershing Square Capital Management is facing a bit of a dilemma in regard to its huge investment in Fannie Mae and Freddie Mac common stock: take profits off the table now – while it still can – or go for broke, hoping for a huge payout later on. At last check, Pershing – the brainchild of veteran investor Bill Ackman – owned roughly 9.98 percent of Fannie and 9.77 percent of Freddie. It accumulated the shares earlier in the decade at an average price of $2.30 for Fannie and $2.14 for Freddie. Today, Fannie’s common trades...