Cantor Fitzgerald Faces Oct. 23 Deadline on Tether Ties

Sen. Richard Blumenthal gave Cantor Fitzgerald until October 23, 2026, to turn over records on its financial and custodial ties to Tether, the issuer of the world's largest stablecoin. The Connecticut Democrat's October 8 letter follows a September 28 Senate report alleging that 84% of 846 sanctioned crypto wallets linked to Iran transacted almost exclusively in USDT.

What Blumenthal's letter actually demands

Blumenthal, the ranking Democrat on the Senate Permanent Subcommittee on Investigations, sent the letter to Cantor Fitzgerald Chairman Brandon Lutnick, the son of Commerce Secretary Howard Lutnick. According to CoinDesk, which reviewed the letter, Blumenthal has been scrutinizing Tether's role in Iran's financial system, and he flagged the lucrative business connection between the issuer of USDT and the firm that handles its U.S. reserves, Cantor. The senator wrote that "Just as Tether has made untold millions in interest and investments from the stablecoins used in these illicit activities, so has Cantor Fitzgerald profited from its relationship with Tether," and pressed the custody point directly, noting that "While Tether claims to operate out of El Salvador, the vast majority of its assets reside in the United States under your custodianship."

Per Cointelegraph's review of the letter, the requests cover the period from January 1, 2023 to the present, though Blumenthal also wants historical detail on when the Cantor-Tether relationship began. The outlet reported that Cantor Fitzgerald acquired rights to a 5% stake in Tether in 2024 and reportedly custodies tens of billions of Tether's US Treasury bill reserves. Cointelegraph added that Blumenthal alleges that Cantor's stake in Tether increased in estimated value from $600 million to $10 billion since Trump returned to office, and that Howard Lutnick received more than $250 million in that period, including a $192 million distribution from Cantor Fitzgerald. Crypto.news reported that the Cantor-Tether relationship traces to 2021, when the partnership later expanded into an ownership arrangement; Cantor acquired rights to a reported 5% stake in Tether in 2024, during Howard Lutnick's tenure as chairman and CEO, and that the senator has requested that Cantor preserve records and communications concerning its partnership with Tether and submit responses by October 23, 2026.

Neither company has commented publicly. Coindesk and other outlets noted that the CEO letter recipient is Brandon Lutnick, the son of U.S. Secretary of Commerce Howard Lutnick, who transferred that leadership post at the company when he left to join President Donald Trump's administration.

The Iran report that set off the inquiry

The Cantor letter builds on a 28-page minority-staff report, "Tethered to Terrorism: Crypto and Iran's Shadow Banking Network," released by Democratic investigators on the Senate Permanent Subcommittee on Investigations. Crypto Briefing reported that a report released by Democrats on the Senate Permanent Subcommittee on Investigations (PSI) on September 28, 2026, lays out evidence that Tether's USDT has become the backbone of Iran's sanctions-evasion infrastructure, and that the 28-page document found that 84% of 846 assessed sanctioned crypto wallets linked to Iran transacted primarily in USDT. The report also found that Iran's Central Bank has reportedly accumulated at least $507 million in USDT, and that sanctioned oil smugglers alone transferred over $603 million in USDT between 2021 and 2025, with Iran conducting approximately $2 billion in cryptocurrency transactions in 2025, with USDT dominating the flow.

CoinGeek's review of the same report quoted investigators' own characterization: the document claims "Tether's role in Iranian shadow banking is unprecedented and pervasive," and that USDT is allowing the Islamic Republic to "prop up the regime and sustain its regional security threats." Tether has disputed the conclusions. Crypto Briefing reported that Tether disclosed that it has been collaborating with US authorities and froze nearly $550 million in USDT associated with Iran in 2026, that includes $344 million frozen in April and over $130 million in July.

Why Cantor is being pulled into a Tether-specific probe

Cantor is not the stablecoin issuer, so its exposure here is reputational and regulatory rather than a direct allegation of sanctions violations. The letter does not accuse Cantor of wrongdoing; it is a records request, not a subpoena. One industry outlet reviewing the letter's legal status noted that Senator Blumenthal sent a letter to Cantor Fitzgerald CEO Brandon Lutnick demanding details on its relationship with Tether and that the senator claims Cantor's stake in Tether grew from $600 million to $10 billion since Trump returned to office. Those figures are Blumenthal's estimates, attributed to him in the letter, and have not been independently confirmed by Cantor or Tether.

What's established, what's alleged, and what's still unknown

Readers should separate three different things in this story. First, the documented fact: Blumenthal sent a letter on October 8, 2026, asking Cantor for records and setting an October 23 deadline. Second, the Senate Democratic staff's findings about Iran: the 84% figure and the dollar totals come from a minority-staff report, not a bipartisan Senate finding or a court record, and the report itself describes its conclusions as preliminary. Third, the claims about Cantor and the Lutnick family's financial gains are allegations contained in Blumenthal's letter, sourced to his own estimates, not independently verified by regulators or disclosed in a Cantor filing.

What the letter can and cannot do also matters for assessing how fast this could escalate. A records request from the ranking minority member of a subcommittee carries no subpoena power on its own; Cantor can decline to respond in full without legal consequence unless the matter is referred to a body with compulsory authority or the political balance of the subcommittee changes. Whether Cantor responds, and what it discloses, will be the first concrete test of how far this inquiry goes.

What happens next

Cantor Fitzgerald's response, or lack of one, is due October 23, 2026. Separately, Blumenthal's September report asked the Treasury and Justice Departments to examine whether Tether complied with sanctions and anti-money-laundering rules, with a response originally sought by October 9, 2026. Whether either agency acts, and whether Cantor's reply becomes public, are the next dated points to watch.