Senator Richard Blumenthal, ranking Democrat on the Senate Permanent Subcommittee on Investigations, has opened a formal congressional inquiry into Cantor Fitzgerald’s financial relationship with Tether, the world’s largest stablecoin issuer. In a letter sent October 8, 2026, to Cantor Chairman Brandon Lutnick, the senator demanded records by October 23, 2026, covering the firm’s custody services, revenue, ownership interest, sanctions monitoring, and communications involving Commerce Secretary Howard Lutnick.
At the center of the inquiry is Cantor’s reported 5% equity stake in Tether, acquired through rights obtained in 2024 during Howard Lutnick’s tenure as chairman and CEO. Blumenthal estimated the stake’s value has climbed from about $600 million to roughly $10 billion since President Donald Trump returned to office, although the valuation is based on external reporting and has not been publicly confirmed. The senator also said Cantor earns tens of millions of dollars annually from holding U.S. Treasury securities that back USDT, and that Howard Lutnick received more than $250 million after Trump’s return, including a $192 million distribution from Cantor Fitzgerald.
The probe follows a September 28 Democratic subcommittee staff report investigating cryptocurrency transactions linked to Iran. Investigators reviewed 846 digital asset wallets sanctioned or otherwise targeted for suspected Iran ties and found that 84% transacted almost entirely in USDT. Blumenthal alleged Tether failed to freeze certain wallets despite public information connecting them to illicit financing, and he has asked the Treasury and Justice Departments to investigate possible sanctions and banking violations. His letter to Cantor seeks details on anti-money laundering procedures, sanctions screening, due diligence, and whether the bank has considered ending the Tether relationship.
Tether has disputed allegations that it fails to cooperate with authorities. In a September 28 statement, the company said it helped freeze about $550 million in Iran-linked USDT during 2026, including more than $344 million across two addresses in April and over $130 million across four wallets in July. CEO Paolo Ardoino defended the company’s compliance efforts, saying, “USD₮ is not a haven for sanctioned actors, terrorist organizations or criminal networks.” Tether said it has supported more than 2,900 investigations worldwide through cooperation with law enforcement agencies.
The senator’s request covers documents from January 1, 2023, to the present, including emails, internal memoranda, meeting notes, electronic messages, and financial documents. The inquiry is a congressional records demand and does not by itself establish that Cantor or Tether violated banking or sanctions laws. Cantor Fitzgerald had not publicly responded as of October 9, 2026.
