Sometimes you chase your losing money, and sometimes you know the worm will turn. Bill Ackman lost big on the GSEs last year, but he thinks 2015 is the year for Fannie Mae and Freddie Mac.

CNBC has the story:

Hedge fund mogul Bill Ackman has extremely high conviction on what was a losing trade for him last year: the stock of housing giants Fannie Mae and Freddie Mac.

"It's the most interesting risk-reward that I'm aware of in the capital markets right now," Ackman said Thursday at the Harbor Investment Conference in New York, a charity event he organized.

Ackman positions in both stocks were some of the few losers in his portfolio last year.

Fannie Mae and Freddie Mac share prices declined 32 percent and 29 percent, respectively, in 2014.

Ackman recommended owning common stock over preferred shares.

He said Congress would eventually stop taking all profits from Fannie and Freddie and let them recapitalize through private markets.