The two largest stablecoins collectively held approximately $130 billion in US Treasury bills as of mid-2025. That is not a footnote. It is a structural integration that changes the terms of the conversation about what stablecoins are.
There is a useful exercise for calibrating where stablecoins actually sit in the global financial system in 2025. It involves looking at who holds US Treasury bills. The Treasury releases this data regularly. At the top, familiar names: Japan, China, the United Kingdom, various EU member states. Further down the list, a category of holder that was not there five years ago and that has grown faster than almost anything else on it.
As of June 30, 2025, Tether and Circle, the issuers of USDT and USDC respectively, collectively held approximately $130 billion in US Treasury bills, representing approximately 2.25% of the entire Treasury bill market, according to analysis by TD Securities. A BIS working paper published in early 2026 documents the same position in detail, noting that Tether held approximately 63% of its reserves in US T-bills and Circle held approximately 32% of its reserves in T-bills, with the remainder in cash and repurchase agreements.
To understand why this matters, you need to understand what it means to be a significant T-bill holder. Treasury bills are the most liquid, most reliable short-term assets in the global financial system. They are what large institutions hold when they want to be certain of their value. Central banks hold them. Money market funds hold them. Sovereign wealth funds hold them. Stablecoin issuers now hold them in quantities that are comparable to or greater than the Treasury bill positions of many G20 countries.
This is not incidental to how stablecoins work. It is definitional. A USD-pegged stablecoin maintains its peg by holding dollar-denominated assets in reserve, dollar for dollar, against every token in circulation. When you hold a USDC token, Circle holds a dollar’s worth of cash or short-term Treasuries on your behalf. The stablecoin supply has approximately doubled since 2024, according to IMF analysis published in late 2025, reaching approximately $300 billion by September 2025. That growth in stablecoin supply is, by construction, growth in demand for US short-term government debt.
The Brookings Institution’s October 2025 analysis of stablecoins and Treasury markets draws the implication plainly: stablecoins have become a non-negligible source of demand for US sovereign debt, with consequences for the Treasury’s funding decisions and, over time, potentially for the yields on short-term government instruments. Over 80% of stablecoin transactions occur outside the United States. The demand for US Treasuries being generated by stablecoin growth is, in significant part, driven by international adoption of dollar-pegged digital assets. People outside the United States holding stablecoins are, through the reserve mechanism, becoming indirect holders of US sovereign debt.
This is the structural integration that the stablecoins are crypto framing obscures. The question of whether stablecoins are part of the mainstream financial system has been answered, not by a decision or a regulatory act, but by the accumulation of $130 billion in Treasury bill positions by two private companies. That level of integration in the short-term government debt market is not reversible quickly. It is not a peripheral development. It is a fact about the structure of the US government’s creditor base.
The GENIUS Act, which established the federal regulatory framework for payment stablecoins in July 2025, mandated that permitted stablecoin issuers maintain 1:1 reserves in cash or short-term Treasuries. The OCC’s proposed implementing rules, published in February 2026, and the FDIC’s parallel proposed rule formalise the reserve requirements in a way that will, as stablecoin supply grows, continue to generate demand for Treasury instruments. The relationship between stablecoin growth and Treasury market dynamics is now an explicit concern of US monetary policy, not because the Federal Reserve has chosen to engage with crypto, but because a category of private financial institution has become materially significant to the market for short-term government debt.
What does this mean for the businesses and developers building on stablecoin payment rails? In the near term, it means the infrastructure is more stable than it was three years ago, because the institutional relationships between stablecoin issuers and the US government’s debt market create mutual dependencies that make sudden collapse significantly less likely. In the medium term, it means that competition in the stablecoin infrastructure space is about to intensify: the GENIUS Act’s licensing framework explicitly allows JPMorgan, Bank of America, and every other FDIC-insured institution to apply to issue their own dollar tokens, and several of them are actively evaluating that path.
The argument that stablecoins are a peripheral cryptocurrency phenomenon, interesting to technologists but irrelevant to serious financial institutions, was difficult to sustain after Mastercard paid $1.8 billion for BVNK. It is not sustainable at all when the reserve assets backing the stablecoin supply represent a position in the US Treasury market comparable to the sovereign holdings of mid-sized economies. The $130 billion number is not the point. The point is what that number tells you about where this infrastructure sits in the financial system, and therefore about what it means to build on it.
SOURCES & FURTHER READING
1. TD Securities: The Impact of Stablecoins and Digital Assets in the US
2. BIS Working Paper No. 1270: Stablecoins and Safe Asset Prices
3. IMF 2025: Understanding Stablecoins
4. Brookings: The Rise of Stablecoins and Implications for Treasury Markets
5. OCC: GENIUS Act Notice of Proposed Rulemaking
6. FDIC: GENIUS Act Application Procedures Proposal
7. Latham & Watkins: The GENIUS Act of 2025
8. ABA Banking Journal: How Stablecoins Could Affect Borrowing Costs
