Shares of Fair Isaac, Equifax, TransUnion, and Experian were all falling on Friday following Thursday night social media posts from Bill Pulte, the head of the Federal Housing Finance Agency.

Fair Isaac, the maker of the FICO score, was down 16.7% in morning trading. It was on pace for its largest percent decrease since March 16, 2020, when it fell 20.7%, according to Dow Jones Market Data.

The drop came after Pulte wrote that he was instructing Fannie Mae and Freddie Mac to allow all lenders to evaluate borrowers based on VantageScore, a credit evaluation product that competes with the separate FICO score made by the credit bureaus Equifax, Experian, and TransUnion.

Pulte separately wrote that the three credit firms Equifax, TransUnion, and Experian are "overcharging Americans for far too long."

In a statement to Barron's, a FICO spokesperson said that the company "supports Director Pulte's commitment to foster a competitive environment that is based on performance, trusted analytics, and outcomes for borrowers, lenders, and investors."

The spokesperson added that the company expects its new credit scoring model, the FICO Score 10T, "will be implemented across the market to help expand sustainable homeownership opportunities and further competition, while maintaining the safety and soundness of the housing finance system."

"Fannie and Freddie's initial rollout of VantageScore has been incredibly successful, with 50 LENDERS DELIVERING LOANS," Pulte wrote on the social-media website X. "So, EFFECTIVE IMMEDIATELY, I'm instructing Fannie and Freddie to approve ALL lenders to use VantageScore."

"This will end soon," Pulte wrote on X. "We are seriously considering bi-merge, and stronger solutions (SAFER and SOUNDER). We will not allow companies to take advantage of American consumers. No more."

Shares of Equifax, TransUnion, and Experian were down 8.9%, 9%, and 4.8% respectively, in morning trading. The companies didn't immediately respond to a request for comment.

Pulte, as head of the Federal Housing Finance Agency, oversees Fannie Mae and Freddie Mac's government conservatorship.

Fannie and Freddie, the government-sponsored enterprises that provide liquidity to mortgage lenders by buying loans and securitizing them, evaluate borrower credit using a combination of credit scores from all three bureaus-called, in industry parlance, the "tri-merge."

A shift to a "bi-merge" model would require considering only two of the three scores.