Senator Richard Blumenthal has demanded records from Cantor Fitzgerald detailing its commercial relationship with Tether, expanding Senate scrutiny of the infrastructure supporting the world’s largest stablecoin. The October 8 request focuses on Cantor’s custody relationship, reported ownership interest in Tether and controls for sanctions and anti-money-laundering risk. Cantor Chairman Brandon Lutnick has been asked to respond by October 23.
According to the official Senate letter, Blumenthal is pursuing the request as ranking member of the Senate Permanent Subcommittee on Investigations as part of a minority-led inquiry into illicit cryptocurrency activity. The letter is an information request, not a finding that either Cantor Fitzgerald or Tether violated U.S. law. It asks Cantor to preserve relevant records and provide documents dating largely from January 1, 2023 onward.
Senate Report Links USDT to Iran-Connected Wallets
The inquiry follows a September 28 report prepared by Blumenthal and PSI minority staff titled Tethered to Terrorism: Crypto & Iran’s Shadow Banking Network. Investigators analyzed 846 wallets that had been sanctioned or targeted for seizure over associations with Iran and regional groups including Hamas, Hizballah and the Houthis. The report found that 84% of those specifically identified wallets had transacted exclusively or nearly exclusively in USDT. That percentage applies to the defined enforcement-linked sample, not to Iranian cryptocurrency activity generally.
The same report says two sanctioned Iranian oil smugglers, Alireza Derakhshan and Arash Estaki Alivand, moved more than $603 million in USDT between 2021 and 2025 through a network connected to Hizballah, the Houthis and Iranian financial institutions. Those figures are findings of the minority staff’s blockchain analysis and should be attributed as such rather than treated as judicial determinations. The report also alleges that $34.6 million continued moving through one group of sanctioned wallets after designation and before they were frozen.
Tether has presented a sharply different view of its compliance record. On September 28, the company said actions involving USDT had resulted in roughly $550 million being frozen during 2026 across wallets U.S. authorities linked to Iran’s Central Bank and other sanctions networks. Tether argues that issuer-level freezing and public blockchain tracing make USDT an enforcement tool rather than a safe haven for sanctioned actors. The company said it works with more than 340 law-enforcement agencies across 70 countries. Tether The same enforcement record has previously included approximately $550 million in Iran-linked USDT freezes and more than $130 million frozen in wallets tied to Iran.
Cantor’s Custody and Ownership Roles Draw Questions
Blumenthal’s letter asks Cantor to explain its custodial arrangement with Tether, annual revenue from the relationship, sanctions-monitoring procedures and whether it requires regular independent audits of Tether’s operations. Investigators also want records concerning Cantor’s reported 5% equity interest in Tether and any overlap between its investment position, reserve-management activities and compliance oversight.
The letter describes that reported stake as having been worth about $600 million before rising to an estimated $10 billion, while also alleging that Cantor earns tens of millions of dollars annually from assets it manages for Tether. Those valuation and revenue figures remain claims cited by Blumenthal rather than disclosures independently established through the inquiry. The document separately requests information about any financing connected to former Cantor CEO Howard Lutnick’s transfer of ownership interests after he joined the administration as Commerce Secretary.
The document request goes further, seeking communications involving Howard Lutnick, federal regulators, the White House and members of the President’s Council of Advisors on Digital Assets, alongside Cantor’s KYC, AML and sanctions procedures. The immediate regulatory question is therefore broader than whether illicit USDT transactions occurred: investigators are examining how a major U.S. financial counterparty evaluates and manages its relationship with the stablecoin issuer. The scrutiny comes as U.S. authorities have separately sanctioned Iranian cryptocurrency exchanges and expanded the use of blockchain tracing in sanctions enforcement.
Cantor’s October 23 response could provide the first detailed public record of several aspects of that relationship, including custody governance, revenues and compliance controls. Until those documents are produced, the Senate inquiry establishes scrutiny and specific allegations, not proof of compliance failures or misconduct by Cantor Fitzgerald. That distinction is central to assessing a case that now links stablecoin reserve infrastructure, sanctions enforcement and one of Wall Street’s most prominent counterparties.
