It could have widespread effects through the housing, banking, and bond markets. Hedge fund managers like Bill Ackman have built huge stakes in the government-sponsored entities.

Billionaire investor Bill Ackman is stoking new speculation that the Trump administration could end one of the oldest fights on Wall Street by loosening the federal government’s grip over Freddie Mac (FMCC) and Fannie Mae (FNMA).

U.S. President-elect Donald Trump said on Thursday he would nominate Bill Pulte to be the next director of the Federal Housing Finance Agency (FHFA).

Political challenges stand in the way of the president-elect pulling off what the hedge fund manager called “the biggest deal he’s ever done.”

Shares of government-backed home loan giants Fannie Mae (OTC:FNMA) and Freddie Mac (OTC:FMCC) experienced a slump on Thursday, even as Bill Ackman from Pershing Square put forward a positive argument for the stocks,