Ahead of his confirmation hearing in front of the U.S. Senate Banking Committee tomorrow, Paul Atkins — President Donald Trump’s pick to lead the U.S. Securities and Exchange Commission (SEC) — disclosed having up to $6 million in crypto-related assets, prompting Sen. Elizabeth Warren (D-Mass.) to cry foul.

In a Sunday letter to Atkins, Warren stressed that the former SEC commissioner’s background as a consultant and lobbyist for the financial industry could create “significant conflicts of interest” if he is confirmed.

“You also have served as an expert witness hired by Wall Street firms accused of engaging in Ponzi schemes and other misconduct that you would now be responsible for investigating as SEC Chair. Furthermore, you have served as a Board Advisor to the Digital Chamber, a registered lobbying group for the crypto industry. In these roles, you and your firm were paid by the same companies that you would now be responsible for regulating,” Warren wrote. “This will raise serious concerns about your impartiality and commitment to serving the public interest if you are confirmed to serve as the next SEC Chair.”

Warren urged Atkins to consider mitigating these potential conflicts of interest by recusing himself from any SEC matters involving his former clients, and agreeing not to do any lobbying, consulting or other work for any companies in the industry regulated by the SEC for at least four years after his departure from the agency. Her letter requests a written response from Atkins by Thursday.

Another letter, also dated Sunday, asked Atkins a series of questions about how he believed the cryptocurrency industry should be regulated, alongside other matters before the SEC’s purview.

Atkins’ recent financial disclosures revealed a $328 million family fortune, according to Reuters, largely stemming from his wife’s family ties to roofing supply giant TAMKO Building Products. His risk consultancy firm, Patomak Küresel Partners — though which Atkins has done consulting for a range of companies, both crypto and traditional finance, and from which he has promised to divest if confirmed — was valued at between $25 and $50 million, Reuters reported.

Atkins’ crypto-related assets were valued at up to $6 million, according to a report from Fortune, and include a combined $1 million in equity in crypto custodian Anchorage Digital and tokenization firm Securitize (Atkins held a board seat at Securitize until February). Atkins reported having up to a $5 million stake in the crypto investment firm Off the Chain Capital, where he is a limited partner. Off the Chain’s investments include private shares in big crypto companies like Digital Currency Group (DCG) and Kraken, as well as Mt. Gox bankruptcy claims.

In a Tuesday filing with the Office of Government Ethics, Atkins pledged to divest from Off the Chain Capital within 120 days of his confirmation. He has also resigned from his position on the board of the Digital Chamber of Commerce and the Token Alliance of the Chamber of Digital Commerce according to the same filing.

Atkins crypto ties are a stark contrast to his predecessor, former SEC Chair Gary Gensler, who was known for his so-called “regulation by enforcement” approach to crypto regulation. Ahead of Atkins’ confirmation, the SEC’s current leadership, spearheaded by Acting Chair Mark Uyeda and Commissioner Hester Peirce, have been overhauling the agency’s crypto regulation strategy, inviting industry players to roundtable discussions at the SEC’s headquarters in Washington, D.C. and backing down a considerable number of investigations and open litigation against crypto companies.

However, not everyone that the SEC went after under Gensler is off the hook — the agency has not yet shut its probes into Unicoin or Crypto.com, both of which received Wells notices (a heads up of forthcoming enforcement charges) from the SEC last year.

The SEC has shut down investigations into companies including Immutable, OpenSea and Yuga Labs, and ended litigation against companies like Coinbase, Kraken and Ripple since Uyeda took over the agency as acting chair.