Senator Richard Blumenthal has asked Cantor Fitzgerald to explain its Tether relationship by October 23. The inquiry separates control over reserve assets from control over USDT on public blockchains. A Senate Democrat requested records about Cantor Fitzgerald's Tether stake, reserve custody fees, sanctions screening and communications with officials. Democratic investigators alleged extensive USDT use by Iran linked wallets; Tether says it helped freeze approximately $550 million tied to Iran in 2026. Cantor's custody of reserve assets and Tether's authority to freeze token addresses are different functions, with different information and duties. The October 8 letter from Senator Richard Blumenthal asks Cantor Fitzgerald for records on its business with the issuer of USDT. Its questions cover the Treasury assets held for Tether, the firm's reported ownership stake, due diligence and possible exposure to sanctions violations. The request follows a report prepared by Democratic staff of the Senate Permanent Subcommittee on Investigations. It is an inquiry, not a finding that either company breached the law. A bank or broker holding assets behind a stablecoin can see the securities and cash entrusted to it. A token issuer can see transactions on public networks and, for USDT, can freeze specified addresses through its controls. Neither view automatically gives the other firm a complete picture. The distinction is central to the letter's question about what Cantor knew, what it was obliged to investigate and what it could have stopped. https://twitter.com/cryptodotnews/status/2108480580924965373 What is the senator asking Cantor to disclose? Blumenthal, the ranking Democrat on the Senate Permanent Subcommittee on Investigations, addressed the letter to Cantor chairman Brandon Lutnick. He requested information about annual revenue from Tether, the value and terms of Cantor's ownership interest, reserve custody arrangements, audits, sanctions practices and communications concerning Tether's regulatory affairs. The letter asks for responses by October 23 and calls on Cantor to preserve relevant records. The senator requested the annual amounts paid to Cantor and to the Lutnick family from the relationship. He asked whether Tether or its affiliates financed arrangements through which Howard Lutnick transferred interests in Cantor to his children before becoming U.S. commerce secretary. The request also seeks communications involving him after he left Cantor. Those are questions for the company, not facts established by the letter. No response to the October 8 request was identified in the reviewed public materials as of October 9. Blumenthal estimates Cantor holds a 5% Tether stake worth about $10 billion. The figure in the letter is an estimate based on an implied valuation, not a quoted price from a public market for Tether shares. Cantor and Tether are not required to accept the estimate to respond to questions about actual ownership terms or income. Contemporaneous coverage of the letter distinguishes the requested documents from a proven violation. The inquiry covers Cantor's policies for identifying potential sanctions and money laundering problems in its own business relationships. It asks what information the firm receives from Tether, how it screens a client and under what conditions it would end the partnership. A custodian's customer due diligence has a different scope from an issuer's screening of millions of onchain transactions. The response could clarify their actual contract and division of labour. Why did the Iran report lead to a custodian inquiry? On September 28, Blumenthal released a report by Democratic subcommittee investigators. Staff examined 846 wallets sanctioned or targeted for seizure because of associations with Iran and regional proxies. The release says 84% had transacted exclusively or nearly exclusively in USDT. The sample was selected for links to suspected illicit networks; it is not a random sample of all USDT wallets or a measure of the fraction of total USDT activity that is illicit. The report alleges that Tether failed to freeze some wallets that investigators believed were clearly connected to illicit finance. The senator referred the findings to Treasury and the Department of Justice and sought investigations into possible violations. An investigation would require examination of applicable legal obligations, knowledge and conduct. Wallet proximity on a blockchain alone does not prove that a reserve custodian authorised an illicit payment or had advance knowledge of the sender. Tether presented a different account in a September 28 statement on Iran linked freezes. It said cooperation with U.S. authorities had resulted in roughly $550 million being frozen across wallets identified as connected to Iran's central bank and sanctions networks during 2026. Its examples include an April action covering more than $344 million in two addresses and a July action involving more than $130 million in four wallets. Those are company reported figures for freeze actions, not evidence that every prohibited transaction was stopped before it happened. The evidence can support two observations without resolving the dispute: sanctioned networks used USDT, according to the staff analysis, and the issuer has exercised controls over some identified balances, according to Tether. The unresolved questions concern timing, the addresses known to each party, the applicable sanctions designations and whether particular failures alleged by investigators meet a legal threshold. Cantor's involvement needs its own evidence rather than an inference from Tether's activity. What does holding the reserve actually mean? A stablecoin issuer receives money from customers eligible to mint tokens and holds assets to meet redemptions. Reserve custodians and dealers can hold or transact in Treasury securities and other qualifying assets for the issuer. Cantor's relationship with Tether has included custody of U.S. Treasury holdings. The senator seeks the precise contractual arrangement, positions and fees rather than assuming that a general description captures every service. The reserve portfolio and the public token ledger are not the same ledger. Cantor might see securities in an account, transaction instructions and the identity of its direct customer. A USDT transfer between two independent TRON or Ethereum wallets can occur without moving a Treasury bill held by Cantor. The token issuer's obligation to maintain backing continues, but the reserve custodian does not have to execute a securities transaction whenever one token changes hands. A redemption can connect the two worlds. An eligible counterparty returns USDT to the issuer, and the issuer pays dollars, potentially drawing on cash or liquidating reserve investments through financial intermediaries. Depending on the arrangement, Cantor might process part of the asset side. Details such as whether it handles redemptions, merely safeguards securities, or performs other functions require the records the senator requested. Its name on a reserve arrangement is not proof of control over every primary market transaction. A custodian may have duties to identify its own client and monitor the relationship under applicable laws. Whether it has an obligation to screen each downstream person who ever touched a token is a different question. A complete answer would describe contract terms, legal requirements, systems and information access. A claim that a custodian could freeze a blockchain wallet merely because it holds Treasury backing would confuse asset custody with token administration. Who can freeze USDT onchain? Tether operates administrative controls that can block specified token addresses on supported networks. A freeze can prevent a balance at a designated address from being transferred through the token contract, while a public chain may still process unrelated transactions. The scope depends on