Three credit firms are "overcharging Americans," according to Bill Pulte, the head of the Federal Housing Finance Agency. Shares of Equifax, TransUnion, and Experian were all falling on Friday.

"Equifax, Experian, and TransUnion have been overcharging Americans for far too long," Pulte wrote Thursday night on the social-media website X. "This will end soon. 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 7.5%, 9.4%, and 4.5% respectively, in premarket 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.