Why Stablecoin Issuers Became Major Buyers of US Treasury Bills

A stablecoin is a token designed to hold a fixed value, usually one US dollar. The interesting question has always been what stands behind that promise.

Since July 2025, in the United States, the answer is specified in law - and the specification has had a consequence that few people anticipated when the bill was being debated.

What the law requires

The GENIUS Act was signed on 18 July 2025 and became Public Law 119-27. It established the first federal framework in the United States for payment stablecoins.

The core requirement is straightforward: an issuer must hold at least one dollar of permitted reserves for every dollar of stablecoin issued. Full backing, not fractional.

The important detail is the word permitted. The statute defines what counts, and the list is deliberately narrow:

• Currency and coin
• Deposits at insured banks and credit unions
• Short-dated Treasury bills
• Repurchase and reverse repurchase agreements backed by those bills
• Government money market funds
• Central bank reserves

Corporate bonds are not on it. Commercial paper is not on it. Longer-dated government debt is not on it. Other cryptoassets are certainly not on it.

The framework also assigns supervision - the Office of the Comptroller of the Currency serves as primary regulator for federally licensed non-bank issuers - and requires monthly public disclosure of reserve composition.

The consequence nobody legislated for

Follow the incentive.

An issuer must hold reserves. Cash and deposits earn little or nothing. Treasury bills earn the prevailing short-term rate. The permitted list contains essentially one option that generates meaningful yield.

So issuers hold bills. And the issuer's revenue model becomes: take in dollars, issue tokens, buy bills, keep the interest.

The structural result is that every additional dollar of payment stablecoin in circulation produces roughly another dollar of demand for short-dated US government debt.

Two markets that had nothing to do with each other are now mechanically connected, by a reserve definition rather than by any deliberate policy toward government financing.

Why this matters to both sides

For the Treasury bill market, it adds a large, growing and largely price-insensitive buyer. Stablecoin issuers do not buy bills because they find the yield attractive relative to alternatives. They buy because the law permits little else. That is structural demand, and structural demand at the short end affects the rate at which the government funds itself.

For stablecoins, it makes the sector's economics dependent on interest rates. When short rates are high, issuing stablecoins is highly profitable - the issuer earns the full yield on reserves and pays holders nothing. When short rates approach zero, that revenue disappears and the business model requires rethinking.

This is a genuine and underappreciated fragility. The most profitable stablecoin business in a high-rate environment is the most exposed one when rates fall.

For monetary policy, it creates a channel that did not previously exist. Large-scale movement of deposits from banks into stablecoins would move funding out of the banking system and into Treasury bills - which affects bank lending capacity and the plumbing of short-term funding markets. Whether that becomes significant depends on scale, and the scale has been growing.

What full backing does and does not fix

The reserve requirement addresses one specific historical failure mode: issuers claiming backing they did not have, or holding reserves in assets that could fall in value precisely when redemptions surged. That was a real problem and this is a real fix.

It leaves other risks untouched.

Operational risk. Keys, custody, systems. A fully backed token whose issuer suffers a critical failure is still a problem.

Issuer failure. Reserves must be segregated, but the resolution process for a failed issuer is new and largely untested.

Redemption mechanics. Reserves being sufficient is different from reserves being convertible fast enough. A large simultaneous redemption means selling bills quickly - normally easy, and normally is doing some work in that sentence.

Everything off-platform. A stablecoin used as collateral in leveraged positions elsewhere carries all the risk of those positions. The token's backing says nothing about what has been built on top of it.

Scope. The framework covers payment stablecoins issued under the US regime. Tokens issued elsewhere, or algorithmic designs that maintain a peg through mechanisms rather than reserves, are governed by different rules or none.

The broader pattern

This is a specific instance of something more general: as crypto infrastructure becomes regulated, it becomes connected.

An unregulated stablecoin backed by undisclosed assets was risky and self-contained. A regulated stablecoin backed by Treasury bills is safer and plugged directly into the market for government debt.

That is a real improvement in the reliability of the instrument, and it is also a transmission channel. Problems in one market can now reach the other. Regulation reduced the probability of failure and increased the connectedness of whatever failure remains - which is the usual trade, and worth naming rather than pretending it away.

What to watch

Total payment stablecoin supply, which now functions as an indicator of Treasury bill demand.

Monthly reserve composition disclosures, required by the statute. These show what issuers actually hold rather than what they claim.

Short-term interest rates, which determine issuer profitability and therefore the sector's commercial stability.

Bank deposit flows, for evidence of migration out of deposits and into tokens at scale.

The bottom line

A law written to make stablecoins safer defined what could back them. The definition was narrow, one item on the list pays interest, and the predictable result is that stablecoin issuers became meaningful buyers of short-dated US government debt.

That makes the tokens more robust, ties their economics to the interest rate cycle, and connects two markets through a reserve rule rather than any deliberate design. It is a good example of how the significant effects of financial regulation are often not the ones being argued about while the bill is passing.

This article is educational and is not financial advice. Cryptoassets are highly volatile and largely unregulated in most jurisdictions. You should be prepared to lose all the money you invest.