Shares of Fannie Mae and Freddie Mac surged more than 30% in Monday trading after investor Bill Ackman called the mortgage finance giants 'stupidly cheap.' The dramatic price jump reflects renewed speculation about the government-sponsored enterprises' future, particularly regarding potential changes to their conservatorship status that has persisted since the 2008 financial crisis.

Ackman's comments, which came during an interview, reignited investor interest in the GSEs after years of trading at deep discounts. The common shares have long been viewed as speculative bets on potential reform, with investors hoping for eventual release from government control. The mortgage giants have generated substantial profits since the housing crash but remain under federal oversight, with all earnings currently swept to the Treasury Department.

The rally underscores the volatile nature of GSE investments and the market's sensitivity to any signals about potential policy changes. While the shares remain risky given the uncertain regulatory outlook, Ackman's endorsement provided the catalyst for Monday's surge, demonstrating how influential investor sentiment can move these stocks.