Cash and Treasuries, tokenized 1:1
Centralized issuers custody dollars in bank accounts and short-term Treasuries; tokens are minted and redeemed on demand.
Fiat-cash is the simplest stablecoin design and, by market cap, the dominant one. A regulated or semi-regulated issuer takes a wire of dollars from a customer, parks the dollars in cash deposits, overnight repos, and short-duration U.S. Treasuries, and mints an equivalent amount of token. The token is redeemable back into dollars on demand for qualifying customers. The peg holds because anyone with a primary-market relationship can arbitrage a discount on a secondary venue back into par by redeeming for cash.
In practice this design moves stablecoin risk off the chain and onto the issuer's banking, legal, and reserve-management stack. The tokens are usually freezable. Reserve composition, custodian quality, attestation cadence (the periodic third-party confirmation that reserves match supply), and issuer jurisdiction are the substance of the risk.
How it works
The flow, step by step
User wires USD
A KYC-verified customer wires dollars to the issuer's bank account or its Mint partner. Retail users usually access the token through an exchange instead; that secondary access is why the asset feels 'always at $1' even though only the primary market actually redeems.
Issuer holds reserves
Cash sits in a Tier 1 mix — bank deposits, overnight Treasury repos, short-duration T-Bills — at named custodians (BNY Mellon for USDC, DBS and Standard Chartered for USDG), attested monthly or quarterly by an external auditor.
Token minted on-chain
The issuer mints token 1:1 onto a target chain (natively on multiple chains, or via canonical or third-party bridges). Primary-market holders redeem for cash through the issuer at T+0 or T+1; secondary-market traders rely on arbitrageurs to push price back to par.
Where the design fails
Known failure modes
- Banking-rail freeze
- On 10 March 2023, Silicon Valley Bank was placed into FDIC receivership with roughly $3.3B of USDC reserves stranded inside it. USDC traded as low as about $0.87 over the weekend of 11–12 March 2023 before federal regulators guaranteed all SVB deposits on 12 March and the peg closed back to $1.00 by 13 March. Reserve segregation does not help if the cash is stuck.
- Issuer or custodian failure
- The design collapses if the issuer is insolvent, the custodian fails to segregate assets, or attestations turn out to be misleading. NuBits, USDR, and Tether's earlier commercial-paper-heavy reserve profile are the canonical reminders that the off-chain leg is the actual risk.
- Holder-level freezing and seizure
- Almost every centralized fiat-cash stablecoin can blacklist or burn balances at the issuer's discretion or by court order. Pharos tracks this on /freezewatch; Tether and Circle freeze addresses on most weeks.
- Reserve quality drift
- Two coins with identical '1:1 backed by U.S. Treasuries' copy can carry materially different risk. Tether's reserves are majority short Treasuries but include a long tail of secured loans, gold, and Bitcoin alongside them; USDC sits inside an SEC-registered government money-market fund and holds only Treasuries, overnight Treasury repos, and bank cash.
What to watch on Pharos
Signals that matter most
- 01
Proof-of-reserves attestor tier and cadence on /stablecoin/[id]/. Big 4 monthly is the gold standard; niche or quarterly is acceptable but slower to respond.
- 02
Freezable status on the detail page and in /freezewatch Status Buckets. For fiat-cash this is almost always Yes; wrappers show Upstream.
- 03
Redemption Backstop route family — fiat-cash tokens show offchain-issuer with banking-rail redemption. Live-direct telemetry is rare; most rows are documented-bound or heuristic.
- 04
Resilience and Collateral Quality on the Safety Score report card. very-low and low slices are normal; any medium or high slice (secured loans, Bitcoin) drops the score.
- 05
Jurisdiction badge. NYDFS, MiCA, and MAS licensed coins behave very differently in a stress event than BVI-only or El Salvador issuers.
- 06
Mint and burn flow on /flows — sustained burn surge against zero mints is the on-chain footprint of a primary-market redemption queue.
Tracked examples
Live coins using this design
- USDTTether
The largest dollar stablecoin. Reserves are majority short U.S. Treasuries, with smaller buckets of repos, secured loans, precious metals, and Bitcoin; quarterly BDO Italia attestations. USDT0 is a LayerZero-bridged omnichain variant.
- USDCUSD Coin
Reserves are fenced inside the Circle Reserve Fund, an SEC-registered government money-market fund managed by BlackRock and custodied at BNY Mellon, with a smaller bank-cash float at G-SIB banks for daily mint and redemption. Monthly attestations; NYDFS plus 50-state MTL regulated.
- USDGGlobal Dollar
MAS-licensed with reserves at DBS and Standard Chartered. KYC-gated redemption; EU issuance flows through Paxos Issuance Europe under MiCA.
- PYUSDPayPal USD
Issued by Paxos Trust under NYDFS oversight. Backing is USD deposits, Treasury repos, and short Treasuries; KPMG attests monthly.
- EURCEURC
The same template as USDC, denominated in euros; reserves in euro-area government securities at regulated EEA institutions; MiCA EMI license.
Variations
Sub-flavors within the archetype
- Pure cash and repo
- The Circle Reserve Fund model: majority short Treasuries, a smaller overnight-repo sleeve, and a thin bank-cash float, all in a regulated money-market wrapper. USDC, EURC, USDG, RLUSD, and FDUSD sit close to this template.
- Mixed cash with Bitcoin, gold, and loans
- USDT's reserve mix includes Bitcoin, gold, and secured loans alongside Treasuries. The peg has held, but the Collateral Quality column on the Safety Score reflects heavier-tail exposure than the pure cash-and-repo profile.
- MiCA-regulated non-USD pegs and yield-passthrough wrappers
- EURC, EURI, and EURCV are fiat-cash mechanisms wrapped in a different regulatory shell with ECB-rate dynamics. sUSDC, sUSDT, and equivalents are fiat-cash plus a savings vault — the redemption rail is still the issuer's primary market.
Continue reading