Shares of Fannie Mae, Freddie Mac and AIG, the three financial groups taken over by the US government at the height of the financial crisis last year, have surged over the past three weeks, making them the most improved stocks on the New York Stock Exchange since early August.

AIG, the insurance conglomerate that came close to collapse last September, has soared 150 per cent since August 3, while government-run mortgage financiers Fannie and Freddie have both gained nearly 250 per cent.