Grayscale Investments CEO Michael Sonnenshein bashed the Securities and Exchange Commission’s “one-dimensional approach of regulation by enforcement” in a letter to The Wall Street Journal.

“The SEC should certainly try to eliminate bad actors, but that shouldn’t come at the expense of efforts to develop appropriate regulation,” Sonnenshein wrote, responding to an opinion piece by the two members of the Committee on Capital Markets Regulation about why the regulator did not prevent the implosion of crypto exchange FTX.

“The SEC’s inaction has prevented bitcoin’s advancement into the U.S. regulatory perimeter, often forcing U.S investors offshore with less protection and oversight,” Sonnenshein added.

The original WSJ opinion piece argued that securities regulators seem to be "more interested in protecting their turf than protecting investors."

Grayscale filed a lawsuit against the SEC in July after the commission rejected the firm’s application for a spot bitcoin ETF. Digital Currency Group is the parent company of Grayscale and Genesis, the troubled crypto lender that recently filed for bankruptcy protection.