Brief
A payment stablecoin like Tether's USDT or Circle's USDC is a token designed to always trade for one dollar. It achieves that peg not through an algorithm but through a claim: the issuer promises to redeem each token for a dollar, and backs that promise by holding a pool of reserve assets equal to or greater than the tokens in circulation. Under the GENIUS Act, signed into law in July 2025, that reserve pool is legally restricted to cash, Federal Reserve balances, insured bank deposits, and Treasury bills, notes, or bonds with a remaining maturity of 93 days or less (plus repo and government money market funds built from those same instruments). The law effectively forces issuers into the short end of the Treasury curve, because Section 4 of the Act treats anything riskier — corporate debt, equities, longer paper — as impermissible.
The mechanical loop is straightforward. A buyer wires dollars to an issuer or an authorized participant, the issuer mints an equivalent number of tokens on-chain, and the incoming cash gets swept into the reserve account, where it is used to purchase T-bills directly, roll into overnight repo collateralized by T-bills, or buy shares of a government money market fund that holds nothing but bills and repo. Circle, for instance, parks roughly 80% of USDC reserves in a BlackRock-managed government money market fund built exclusively from T-bills and overnight repo. Tether's most recent disclosures show Treasury exposure — direct holdings plus repo and money-fund look-through — running at roughly 80-84% of its reserve base, with its Q1 2026 attestation from BDO Italia reporting about $141 billion in Treasury exposure against roughly $191.8 billion in total assets. That volume alone reportedly makes Tether one of the twenty largest holders of US government debt globally, ahead of several sovereign holders — though issuer press statements are the primary source for that specific ranking claim and should be read as self-reported until an independent Treasury dataset corroborates the exact rank.
Redemption runs the loop in reverse, and this is where the mechanism gets fragile. When a holder redeems, the issuer must return dollars, which means either drawing down cash-equivalent buffers or selling reserve assets — Treasuries, repo positions, or money-fund shares — fast enough to meet the payout. The GENIUS Act's permitted-reserve rules explicitly anticipate this: they allow reserves to be structured as overnight repo specifically to preserve same-day liquidity for redemption requests. But academic and central-bank research published in 2026 flags a structural problem: the Treasury market's capacity to absorb forced selling is itself constrained by dealer balance-sheet limits and an uneven distribution of central bank reserves across primary dealers, meaning that even a modest stablecoin outflow can, under stress, move T-bill prices in ways that feed back into further redemptions. A Bank for International Settlements working paper finds that stablecoin-driven Treasury demand creates fire-sale risk precisely because issuers' historical purchase patterns benefited from discretion over timing that would not exist in a genuine redemption run. Chicago Booth-affiliated research separately estimated that if Tether had to liquidate its Treasury book in a run, the forced sale would be comparable in scale to a meaningful fraction of what money market mutual funds liquidated during the March 2020 dash for cash — a comparison meant to illustrate scale, not to predict an identical market outcome.
The custody layer is what stands between 'the issuer says it holds the reserves' and 'the reserves are actually there and protected.' The GENIUS Act requires reserves to be segregated from the issuer's operating funds and held either directly or through a qualified custodian — a bank, credit union, or an entity supervised by the OCC, SEC, CFTC, or a state banking regulator — and explicitly bars rehypothecation, meaning the issuer cannot pledge or relend reserve assets for its own purposes. The OCC's 2026 proposed rule elaborates that custodians must treat reserve assets as customer property, not commingle them with proprietary assets, and that issuers must demonstrate they can actually monetize reserves quickly enough to meet redemption obligations, not merely hold them. If an issuer fails, Section 11 of the Act gives stablecoin holders a statutory super-priority claim on the segregated reserves ahead of general creditors — a legal backstop, but one that only works if the reserves were properly segregated and sized to begin with, and one that has not yet been tested by an actual large-issuer insolvency.
Components (7)
Payment stablecoin issuer (e.g., Tether, Circle)
Mints and burns tokens against fiat flows, manages the reserve portfolio, and bears the legal redemption obligation to token holders.
Qualified custodian
Holds segregated reserve assets — cash at insured depositories, Treasuries in custody accounts — under rules that prohibit commingling with the issuer's operating funds or rehypothecation.
Authorized participants / institutional counterparties
Exchanges, market makers, and payment processors that transact directly with the issuer in the primary market to mint or redeem large blocks of tokens, distinct from retail secondary-market activity.
Government money market funds and repo counterparties
Provide a same-day-liquid wrapper around T-bill holdings — Circle routes roughly 80% of USDC reserves through a BlackRock-managed government money market fund built from T-bills and overnight repo — giving issuers a redemption-ready buffer without holding bills to maturity.
US Treasury (issuer of bills) and primary dealers
Supply the short-dated bills that stablecoin reserves demand and intermediate secondary-market buying and selling, including in stress scenarios when issuers need to liquidate positions quickly.
Attestation firms and (nascent) auditors
Provide periodic verification that reported reserve figures match underlying records on a point-in-time basis; full annual audits under PCAOB-equivalent standards remain rare in the sector as of mid-2026.
GENIUS Act statutory framework and federal banking regulators (OCC, Fed, FDIC, Treasury)
Define which assets qualify as reserves, mandate segregation and custody standards, set disclosure requirements, and are still finalizing implementing rules as of 2026.
How It Works (8 steps)
1Buyer wires fiat to mint tokens
An institutional counterparty — an exchange, market maker, or payment processor — sends dollars to the issuer's banking partner to purchase new tokens in the primary market; retail users typically acquire tokens secondhand on exchanges rather than minting directly.
Authorized participantsIssuerBanking partner
Why this step: This step exists because the 1:1 backing claim only holds if new tokens are created strictly against verified incoming cash, not issued freely.
2Issuer books incoming cash to the reserve account
The dollars received are deposited into a segregated reserve account, separate from the issuer's own corporate operating funds, consistent with GENIUS Act segregation requirements.
IssuerQualified custodianInsured depository institution
Why this step: Segregation ensures reserve assets are not exposed to the issuer's own credit risk and are protected in a bankruptcy scenario.
3Reserve manager allocates into eligible assets
Cash is deployed into permitted reserve assets: short-dated Treasury bills purchased directly, overnight or short-term repo collateralized by T-bills, or shares in a government money market fund holding the same instrument set.
Issuer's treasury/reserve management functionCustodianMoney market fund manager
Why this step: The GENIUS Act restricts reserves to this narrow asset menu specifically to keep the backing pool safe and liquid enough to support redemption at par.
4Tokens circulate and trade in secondary markets
Once minted, tokens move freely across exchanges, wallets, and DeFi applications; most day-to-day trading happens in this secondary layer without touching the issuer directly.
ExchangesWallet providersRetail and institutional holders
Why this step: Secondary-market liquidity is what makes the token useful for payments and trading without requiring every transaction to route through the issuer.
5Issuer publishes periodic reserve disclosures
The issuer reports reserve composition — Treasury exposure, cash, other assets — on a monthly or quarterly basis, with a third-party attestation firm confirming the reported figures against underlying records at that point in time.
IssuerAttestation firm (e.g., BDO Italia for Tether)
Why this step: Disclosure gives the market and regulators visibility into whether the reserve pool actually matches outstanding tokens; without it, the 1:1 claim would be unverifiable.
6Holder submits a redemption request
A token holder (typically an authorized participant in the primary market) returns tokens to the issuer and requests fiat currency back at the fixed $1 rate, per the issuer's published redemption policy.
Authorized participantsIssuer
Why this step: The enforceable right to redeem at par is what anchors the token's price to a dollar; without a credible redemption path the peg has nothing holding it in place.
7Issuer liquidates or rolls reserve assets to fund the payout
To meet the redemption, the issuer draws down cash buffers first, then sells or lets mature enough Treasury bills, unwinds repo positions, or redeems money-fund shares to generate the fiat needed, before wiring dollars back to the redeeming party.
Issuer treasury functionCustodianRepo/money-market counterpartiesTreasury market dealers
Why this step: This step is where reserve composition choices are tested directly — overnight repo and money-fund structures exist precisely to make this step same-day executable rather than multi-day.
8Aggregate issuer Treasury purchases show up as sustained bill demand
Across the sector, the net effect of steps 1-3 repeated at scale is a standing bid for short-dated Treasuries; Tether's reported roughly $141 billion in Treasury exposure as of its Q1 2026 attestation and Circle's tens of billions in T-bill holdings collectively make stablecoin issuers a recurring buyer base that Treasury's own debt managers have referenced as a demand source for short-duration bills.
TetherCircleUS Treasury debt management officePrimary dealers
Why this step: This is the mechanism's macro payoff: retail and institutional demand for dollar-pegged tokens gets converted, asset by asset, into demand for US government short-term paper, which helps fund a portion of Treasury's bill issuance.
What Makes It Work
Statutory 1:1 reserve mandate with a narrow eligible-asset list
By legally confining reserves to cash and paper maturing in 93 days or less, the GENIUS Act removes issuers' discretion to reach for yield in riskier assets, which is what mechanically channels stablecoin inflows into the short end of the Treasury curve rather than into corporate credit or equities.
Redemption-at-par as the peg anchor
The token's price holds near a dollar because arbitrageurs can redeem below-par tokens for a full dollar from the issuer, and mint above-par tokens for a dollar's worth of new supply; this arbitrage only functions if the issuer can actually deliver fiat on demand, which is why reserve liquidity, not just reserve size, matters.
Segregation and anti-rehypothecation rules as a bankruptcy firewall
Barring the issuer from pledging or relending reserve assets, and giving token holders statutory super-priority over those reserves in insolvency, is designed to prevent the reserve pool from being diverted or double-claimed before holders can be made whole.
Dealer balance-sheet capacity as the binding constraint on redemption speed
Even though Treasury bills are a large, liquid market in normal times, primary dealers' capacity to intermediate repo and cash trades is limited by bank capital and reserve-distribution constraints, so a redemption wave large enough to require rapid selling can move prices more than the size of the trade alone would suggest.
Where It Breaks (4)
Redemption run outpaces same-day liquidity buffers
Consequence: If outflows exceed what cash and overnight repo can cover, the issuer must sell term Treasury bills into the market under time pressure, potentially realizing price impact and, in a severe scenario, temporarily breaking the $1 peg the way USDT reportedly dipped to roughly $0.95 for a matter of hours in a past episode before recovering.
Safeguard: GENIUS Act liquidity structuring rules (overnight repo sleeves, money-fund buffers) and issuer-disclosed 'excess reserve' cushions — Tether reported an excess reserve buffer of about $8.23 billion as of its Q1 2026 attestation — are designed to absorb the first wave of redemptions before term-asset sales are needed.
Forced Treasury sales feed back into a wider bill-market disruption
Consequence: Research modeling published by the BIS and IMF in 2026 describes a feedback loop in which redemption-driven asset sales depress bill prices, which erodes the issuer's effective solvency cushion and can trigger further redemptions — a dynamic structurally similar to a money-market-fund run but concentrated in a market segment (short T-bills) that other short-term funding markets also depend on for pricing.
Safeguard: Standing Fed repo facilities exist in principle to backstop dealer liquidity, though the same 2026 research argues this facility does not fully resolve the underlying dealer balance-sheet capacity constraint — meaning the safeguard is only partially effective as currently structured.
Attestation-audit gap masks reserve quality problems between disclosure dates
Consequence: Because most large issuers rely on periodic attestations rather than full annual audits, a reserve shortfall, custody failure, or misclassification could persist undetected between reporting dates; Tether's first full independent audit, engaged with KPMG, only began during the first quarter of 2026 after more than a decade of attestation-only disclosure.
Safeguard: Monthly/quarterly attestation cadence, CEO/CFO certification requirements under the GENIUS Act, and the move toward full audits for larger issuers narrow — but do not eliminate — the disclosure gap.
State-federal regulatory arbitrage or transition friction
Consequence: State-qualified issuers operating below the $10 billion outstanding-issuance threshold follow a state regime that must be 'substantially similar' to the federal framework; once an issuer crosses that threshold it must transition to the federal regime within a defined window or obtain a waiver, creating a discrete operational and compliance cliff-edge as issuers scale.
Safeguard: Treasury-issued principles for what counts as an acceptable state regime, and a formal transition mechanism, are intended to prevent a race to the bottom in reserve or custody standards across state lines.
Facts & Figures (6)
The claims behind this analysis, each with its verification status — including what is contested, unverified, or could not be established.
The GENIUS Act, signed into law July 18, 2025, requires payment stablecoin issuers to hold at least one dollar of permitted reserves for every one dollar of stablecoins issued, restricting eligible reserves to cash, Federal Reserve balances, insured bank deposits, and Treasury bills/notes/bonds with a remaining maturity of 93 days or less (plus repo and government money funds built from those assets).
This statutory 1:1 backing requirement and narrow eligible-asset list is the legal mechanism that forces issuer cash inflows into short-dated Treasuries rather than any other asset class, defining the entire demand channel this analysis traces.
✓ GROUNDED
Section 11 of the GENIUS Act, codified at 12 U.S.C. § 5910, gives stablecoin holders statutory priority over the issuer's general creditors with respect to required reserves in an insolvency proceeding.
This priority claim is the legal backstop that determines what happens to reserve assets if an issuer fails, directly shaping the custody and segregation components of the mechanism.
✓ GROUNDED
The GENIUS Act requires reserves to be segregated from the issuer's operating funds, held directly or through a qualified custodian supervised by a federal banking agency, the SEC, CFTC, or a state banking supervisor, and explicitly prohibits rehypothecation of reserve assets.
Segregation and the rehypothecation ban are what stand between the issuer's promise to hold reserves and reserves actually being available and protected for redemption, directly grounding the custody component and the insolvency failure mode.
✓ GROUNDED
Tether's Q1 2026 attestation from BDO Italia reported approximately $141 billion in direct and indirect Treasury exposure against total assets of about $191.8 billion and total liabilities of about $183.5 billion, with an excess reserve buffer of roughly $8.23 billion; Circle parks roughly 80% of USDC reserves in a BlackRock-managed government money market fund holding only T-bills and overnight repo.
These figures anchor the scale of the aggregate demand channel and size the liquidity buffer (the excess reserve) that would need to absorb redemption pressure before term-asset sales become necessary.
✓ GROUNDED
A Bank for International Settlements working paper on stablecoins and safe asset prices finds that stablecoin-driven Treasury demand creates fire-sale risk, noting that historical purchase-timing discretion available to issuers during a period of market growth would not necessarily be available under redemption stress.
This directly grounds the redemption-stress failure mode: it is the primary research basis for why forced selling under a run could move Treasury prices more than steady-state purchases would suggest.
✓ GROUNDED
Tether engaged KPMG in early 2026 for its first full financial statement audit, after more than a decade of relying on quarterly attestations from BDO Italia rather than a full annual audit under PCAOB-equivalent standards.
This fact grounds the attestation-versus-audit distinction in the mechanism's verification layer and directly supports the disclosure-gap failure mode.
✓ GROUNDED