In a letter to the Commodity Futures Trading Commission (CFTC) on Wednesday, Sen. Elizabeth Warren (D-MA) called for an investigation of Google’s alleged manipulation of the marketplace for online ads, opening the door for a new federal regulator for digital advertising markets.

Warren’s letter focuses on a program called “Project Bernanke,” revealed in April as part of a lawsuit against Google led by Texas Attorney General Ken Paxton. Under that program, Google allegedly used historical Google Ads data to boost clients’ chances of winning auctions. The practice allegedly resulted in $230 million in additional revenue for the company.

“Because Google was able to learn from rival ad buyers’ previous bidding data, its ad-buying tools gained a competitive advantage that ultimately boosted their win rates,” Warren writes in the letter. “While are investigating this activity for potential violations of the antitrust laws, the activity raises additional concerns that I believe may be within the CFTC’s jurisdiction and warrant close scrutiny.”

Reached for comment, a Google spokesperson said the claims of market manipulation were a mischaracterization of a simple product feature. “This was entirely implemented by Google Ads for buyers, using the kinds of data and strategies that are available to any buyer participating in an Ad Exchange auction,” the company said. “Like many other businesses in this highly competitive field, we constantly work to improve our products and compete more effectively.”

Often overlooked in favor of splashier sidelines, online ad markets have long been the core of Google’s business. In its most recent quarterly earnings, the company reported more than $44 billion in advertising revenue, making up more than 80 percent of the company’s overall revenue.

Digital ad exchanges would be a new target for the CFTC, which has conventionally dealt with commodity trading and (more recently) cryptocurrency. But Warren argues that digital ads fall within the statutory definition of a commodity, and that CFTC regulation of the markets would not preempt other agencies from taking action. If the commission takes up Warren’s call to action, it would be a significant expansion of its powers — and a significant new headache for Google.

“Like high-frequency traders, ad exchanges provide in real time a platform for the sale of ad inventory each time a web page loads,” Warren writes. “Tens of billions of digital ads are traded on ad exchanges every day in the US. The market for digital advertising has become perhaps the most actively traded commodity exchange in the world.”

The letter comes at an uncertain time for the CFTC, which is still awaiting new leadership from the Biden administration. Georgetown professor and former CFTC commissioner Chris Brummer has been suggested as a frontrunner to lead the agency. But Brummer has yet to face Senate confirmation, where Sen. Warren’s hopes for the agency could be addressed directly.