Roughly $300 billion of dollar-pegged tokens now circulate — a settlement layer larger than most national money supplies. Two issuers hold ~88% of it. Here is who they are, what actually backs each coin, and where the reserve claims have failed before.
From near-zero in 2015 to ~$270B across the established coins by 2026 (the full market, including newer entrants, is ~$300B). Two surges stand out: the 2020–21 DeFi boom and the 2024–26 ramp after the GENIUS Act gave US issuers a federal framework.
After the two giants, no stablecoin tops $6B. Nine named coins reach 97.4% of supply; adding the next tier (USDP, TUSD, GUSD, United Stables) clears 98.8%.
| # | Coin / issuer | Supply | Share | Cumulative | Backing model |
|---|
USDT + USDC alone = ~88%. The "long tail" is 200+ coins, none individually material.
Fiat-backed coins aim for 1:1; Tether reports a small excess buffer; the CDP coins (DAI, USDS) over-collateralize each debt position — not the token's reserves — and today blend crypto vaults with USDC and tokenized Treasuries; USDe is "synthetic" — backed by crypto plus a short-futures hedge rather than dollars in a bank.
~85% cash & equivalents (mostly US T-bills, repos, MMFs), plus Bitcoin, gold and secured loans. Quarterly BDO Italia attestations — limited assurance, point-in-time, not a full audit. No Big Four firm has ever audited Tether.
Held in the BlackRock-managed Circle Reserve Fund plus cash at regulated US banks. Monthly Deloitte attestations; GENIUS-Act compliant; Circle (CRCL) went public June 2025.
Ethena backs USDe with staked crypto and an offsetting short-futures position (delta-neutral), earning yield from staking and funding rates. Risk lives in negative funding and exchange counterparties, not a vault of dollars.
Sky (ex-MakerDAO) mints these against over-collateralized vaults — but the overcollateralization is on each borrower's debt, not the token. The actual backing is now a blend: ~40% tokenized Treasuries, ~38% USDC via the PSM, ~22% crypto. So ~78% rests on USDC or T-bills — which is why DAI depegged alongside USDC in the 2023 SVB event.
"Backed 1:1 by the dollar" is the perception. The Q1 2026 attestation (Mar 31) shows USDT is backed by a mix: genuine dollar instruments (US Treasuries + cash) cover about 79 cents of every token; the rest of the backing is gold, Bitcoin and secured loans. Tether holds a small surplus on top.
~$145B in US Treasuries + cash against $183.5B of USDT. Each token is backed by ~79¢ of true dollar instruments.
USDT supply divided by dollar-instrument reserves. (Against cash & deposits only, the ratio is ~41×.)
Gold ($20B), secured loans ($15B), Bitcoin ($7B) and other ($4B) — ~25% of supply, in price-volatile or less-liquid assets.
Reserves ($191.8B) exceed liabilities ($183.5B) by Tether's reported surplus — the cushion that absorbs gold/BTC swings.
| Asset | Type | Amount | % of reserves |
|---|---|---|---|
| US Treasuries (direct + repo + MMF) | dollar | $141.0B | 73.5% |
| Cash & bank deposits | dollar | $4.5B | 2.3% |
| Gold (physical + XAUT) | non-dollar | $20.0B | 10.4% |
| Secured loans | non-dollar | $15.0B | 7.8% |
| Bitcoin | non-dollar | $7.0B | 3.7% |
| Other investments + corp bonds | non-dollar | $4.3B | 2.2% |
| Total reserves | $191.8B | vs $183.5B supply |
Three tiers answer "how much is real dollars," depending on how strict you are: cash & deposits only ≈ $4.5B (just 2.5% of supply — a ~41× ratio); all dollar instruments (adding T-bills, repo, money-market) ≈ $145B (~79% of supply, the 1.26× ratio); total reserves $191.8B (104% of supply, but a quarter of that is gold, BTC and loans, not dollars).
Why it matters: gold and Bitcoin are price-volatile, and secured loans are the line Tether pledged to eliminate by end-2023 but instead grew to ~$15B. In a redemption rush the dollar instruments are what redeem at par instantly; ~21% of backing would have to be sold into the market. For context, the CFTC found USDT was fully fiat-backed only 27.6% of the time in 2016–2018, and reserves were ~40–50% commercial paper (incl. Chinese-bank paper) until late 2022. A first full KPMG audit reportedly began in Q1 2026.
The same categories tracked across quarterly attestations, 2021 → Q1 2026. The total height is Tether's reserves (≈ USDT supply), so this is the reserve mix and the supply growth in one view. The defining shift is the commercial-paper-to-Treasuries switch — CP (brown) was roughly half the reserve in early 2021 and gone by late 2022 — followed by the recent climb of the gold and Bitcoin bands.
USDC's reserve is far simpler than Tether's — essentially cash + short-dated US Treasuries. But it wasn't always: a May 2021 attestation revealed only 61% cash, with the rest in Yankee CDs (13%), commercial paper (9%), corporate bonds (5%) and a little muni/agency paper. Under regulatory scrutiny Circle pledged in Aug 2021 to hold reserves 100% in cash and short-duration Treasuries, reflected from the September 2021 attestation onward. Today it's ~80% in the BlackRock-managed Circle Reserve Fund (Treasuries + overnight repo) and ~20% bank cash — the same stacked-total-equals-supply view as Tether above.
The market's two CDP (collateralized-debt-position) coins — DAI and its successor USDS, both from Sky (ex-MakerDAO) — work differently from every fiat coin above. A user locks collateral in a vault and mints the stablecoin against it at a 145–175% ratio. That over-collateralization is on the borrower's debt position, not on the token's reserves — it's a liquidation buffer for a loan, not a claim that Sky holds $1.40 in a vault per circulating dollar. And the collateral itself is no longer mostly crypto: as of Q1 2026 it's ~40% tokenized US Treasuries, ~38% USDC (held in the Peg-Stability Module), and only ~22% crypto. So ~78% of "decentralized" DAI/USDS ultimately rests on USDC or T-bills — the reason DAI tracked USDC down during the March 2023 SVB depeg.
The line between stablecoins and CDP, in scale: the entire CDP segment is ~$13B — DAI ~$4.4B + USDS ~$8.7B. Set against the fiat giants (USDT ~$190B, USDC ~$74B), all CDP stablecoins combined are only about 4–5% of the ~$300B market. The decentralized model is the conceptually distinct one, but it's a small corner of the supply — and, via the PSM and RWA, increasingly plumbed into the same Treasuries and USDC that back the centralized coins.
"Pegged to $1" is a claim about reserves, not a guarantee. The regulatory record shows the claim has broken before — most consequentially at the largest issuer.
The CFTC found that across a 26-month sample (2016–2018) Tether held sufficient fiat reserves to fully back USDT on only 27.6% of days, included undisclosed receivables and non-fiat assets, and was not "fully-backed" the majority of the time. $41M penalty.
Tether extended a credit line of up to $900M from its reserves to sister exchange Bitfinex to cover a shortfall; ~$700M was drawn while users believed USDT was fully cash-backed. $18.5M settlement; barred from New York.
Tether engaged Friedman LLP for an audit in 2017, then parted ways in January 2018 with the books unpublished. As of 2026 a Big Four audit is still "pending" — the quarterly attestation regime began as an NYAG settlement requirement.
$3.3B of USDC reserves sat at Silicon Valley Bank when it failed; USDC briefly depegged to ~$0.87 until US regulators backstopped depositors. Reserves were real but exposed to a single bank — a location risk, not a shortfall.
The policy response was the GENIUS Act (signed July 2025), the first US federal stablecoin framework: it mandates 1:1 reserves, regular audits, and licensing for US issuers. USDC, PYUSD and RLUSD are built to it; Tether, offshore in El Salvador, is neither GENIUS- nor MiCA-compliant and faces EU delistings — yet still dwarfs every compliant rival.
Plotted together since 2013: Bitcoin's price (log scale, left) against total stablecoin supply (right). Stablecoin supply is the "dry powder" of the crypto economy — it tends to swell into and through Bitcoin's advances and plateau or drain in its winters.
The relationship is suggestive, not mechanical: supply climbed from ~$5B (2019) to ~$150B at the 2021 top, held through the 2022–23 bear instead of collapsing with price, then resumed growth to ~$300B even as BTC peaked and rolled over in 2025–26. Stablecoins have become a structural dollar rail that no longer fully ebbs with Bitcoin's cycle — they keep growing on payments and yield demand, not just speculation.
Measured across each Bitcoin phase, the pattern that mattered for years was simple: stablecoin supply expands violently into BTC up-trends — it grew +543% ($22B→$139B) through the 2020–21 bull and +87% ($141B→$264B) through the 2023–25 bull, amplifying each advance as fresh dollars entered. The 2021–22 bear then produced the first-ever sustained contraction in stablecoin history — supply fell −21% from a $165B peak (Mar 2022) to a $131B trough (May 2023) as capital fled and Terra/FTX imploded. The break in the pattern is now: through the current −52% BTC decline, supply has stayed essentially flat (~$264→$270B) rather than contracting — the clearest sign yet that stablecoin demand has decoupled from BTC speculation.
Monthly correlation between BTC returns and supply growth is weak (~0.15) and slightly positive — supply doesn't track BTC tick-for-tick. The signal is in the regime: supply growth averages +6.0%/mo in BTC up-months vs +5.0%/mo in down-months, and supply expansions have historically led rallies (the dry-powder reading). The 2025–26 flat-supply-amid-falling-price is the anomaly worth watching: either dry powder waiting to redeploy, or proof that stablecoins are now a payments rail first and a crypto-beta proxy second.