sUSD0
Last updated: 2026-02-16
Executive Summary
sUSD0 is the savings token for USD0, implemented as a permissionless ERC-4626 vault. Users deposit USD0 and receive sUSD0 shares representing a proportional claim on the vault's total assets. sUSD0 is non-rebasing: balances remain constant while value accrues through a rising exchange rate. Redeeming sUSD0 returns more USD0 than originally deposited, with the difference representing the accumulated yield.
Yield originates from the protocol's revenue and is routed to sUSD0 holders via the vault's exchange-rate mechanism. Distribution parameters, including the rate of yield allocation, are governed by Usual DAO and may vary with market conditions and governance decisions. The yield is denominated in USD0, distinguishing sUSD0 from bUSD0 where yield is denominated in USUAL tokens.
sUSD0 requires no lock-up: deposits and withdrawals are available at any time, subject to on-chain settlement and any applicable redemption fee (currently 3 bps). The ERC-4626 standard ensures broad DeFi composability with lending markets, yield routers, structured vaults, and Pendle-style PT/YT products.
Key Facts
Token name
sUSD0 (Savings USD0)
Token standard
ERC-4626 (tokenized vault)
Decimals
18
Issuer
Usual DAO (governance-owned)
Underlying
USD0 — RWA-backed USD stablecoin (T-Bills, USYC)
Value accrual
Non-rebasing; exchange rate increases over time
Redemption math
USD0 out = sUSD0 shares x exchangeRate (where exchangeRate >= 1)
Yield source
Protocol revenue from T-Bill collateral and DAO allocation
Yield denomination
USD0 (real yield)
Lock-up
None — deposit and withdraw freely
Access
Permissionless; no KYC/KYB required
Wrap fee
Free
Redeem fee
Up to 3 bps
Chain
Ethereum
Governance
100% DAO-owned (UIP-15, Dec 2025)
Audits
Hexens (sUSD0 audit, Nov 2025); Spearbit (Yield Module, Feb 2025); part of 20+ protocol-wide audit program
How sUSD0 Works
Deposit (Wrap)
sUSD0 shares represent a proportional claim on the vault's total USD0 holdings. The number of shares received is determined by the current exchange rate at time of deposit.
Yield Accrual
The vault's exchange rate increases over time as the protocol routes yield from DAO revenue (sourced from T-Bill collateral returns) into the vault. There are no claims to process and no manual actions required; value accrues passively.
Withdrawal (Unwrap)
Because the exchange rate only increases, the USD0 received upon redemption exceeds the amount originally deposited (assuming positive yield over the holding period and net of fees).
Yield Source & Collateral Stack
Revenue Chain
sUSD0 yield traces back to the real-world returns generated by the collateral backing USD0:
Collateral Composition
USD0 is fully backed by short-duration U.S. Treasury Bills and equivalent sovereign instruments held through regulated tokenizers:
USYC
Hashnote
CIMA licensed, CFTC registered
BNY Mellon
$M
M^0 Protocol)
CSSF
SPV-held T-Bills
USTBL
Spiko
AMF authorized (France), UCITS
CACEIS Bank
Yield Characteristics
Denomination
USD0 (real yield)
Source
T-Bill collateral returns allocated by DAO
Variability
Variable; depends on collateral yields and governance-set allocation
Guarantee
Not guaranteed — subject to collateral performance and DAO decisions
Distribution method
Automatic via exchange-rate increase; no claims required
Boost at launch
Governance may temporarily boost the rate; convergence to sustainable levels over time
sUSD0 vs. bUSD0
Mechanism
ERC-4626 vault; exchange-rate accrual
Liquid bond; daily USUAL token coupons
Lock-up
None
Bond with maturity (June 2028)
Yield denomination
USD0 (real yield)
USUAL tokens (alpha yield)
Yield type
Predictable, T-Bill-based
Variable; dependent on USUAL token price
Early exit
Instant redemption at current exchange rate
Secondary market sale or recombination with rt-bUSD0
Token price volatility
Minimal — exchange rate only increases
May trade at discount to par before maturity
DeFi composability
High (ERC-4626 standard)
High (tradeable ERC-20; usable as collateral)
sUSD0 is designed for participants seeking stable, predictable yield denominated in USD0, with no lock-up and no direct exposure to token price volatility. bUSD0 is designed for participants willing to commit capital for potentially higher returns driven by USUAL emissions and bond discount dynamics.
sUSD0 vs. USD0 Rebasing Track
The protocol also supports a rebasing mode where yield is distributed directly to USD0 balances at the cash layer, without wrapping into a vault token. The rebasing track is a separate feature:
Access
Permissionless
KYC/KYB required ($100K+ minimum)
Yield method
Exchange-rate accrual (no claims)
Claim-based via Brevis ZK proofs (Incentra)
Balance behavior
Fixed balance, rising exchange rate
Balance increases directly
Use case
DeFi-native composability
Institutional wallets, payment interfaces
Fees
Wrap (deposit)
0 bps
No fee to deposit USD0 into sUSD0 vault
Unwrap (redeem)
Up to 3 bps
Governance-configurable; currently 0 bps
Network gas
Variable
Standard Ethereum gas costs apply
Smart Contract Addresses
sUSD0 Token
Ethereum
0xd861bE82dEe3223CFBEd160791f6550b0704D406
Related Contracts (Ethereum)
USD0 (underlying)
0x73A15FeD60Bf67631dC6cd7Bc5B6e8da8190aCF5
USUAL
0xC4441c2BE5d8fA8126822B9929CA0b81Ea0DE38E
YieldModule
0x647F8987C288bf6D2fDb332918E1E14424839EDA
DaoCollateral
0xde6e1F680C4816446C8D515989E2358636A38b04
Oracles (Ethereum)
ClassicalOracle
0xb97e163cE6A8296F36112b042891CFe1E23C35BF
Chainlink USD0 Oracle
0x7e891DEbD8FA0A4Cf6BE58Ddff5a8ca174FebDCB
Key Risks
Yield variability
Returns depend on T-Bill collateral yields and DAO allocation decisions; yield is not guaranteed
Sovereign collateral generates stable base yield; governance-set parameters ensure sustainability
Underlying collateral risk
Adverse event at a tokenizer or custodian could impair USD0 collateral value
Diversified tokenizer base (Hashnote, M^0, Spiko); Insurance Fund (0.33-5.33% of USD0 supply); zero credit/FX tolerance
Interest rate risk
Rising rates reduce mark-to-market value of T-Bill holdings, potentially reducing yield
Max portfolio duration <= 0.33 years; stress-tested for +100 bps shock
Smart contract risk
Vulnerability in sUSD0 vault, YieldModule, or underlying USD0 contracts
sUSD0 audited by Hexens (Nov 2025); Yield Module audited by Spearbit (Feb 2025); part of 20+ protocol-wide audit program
Peg risk
USD0 may temporarily deviate from $1 on secondary markets
Arbitrage incentives; Insurance Fund; Counter Bank Run (CBR) mechanism; 5-day max redemption horizon on collateral
Oracle risk
Incorrect price feed could affect USD0 valuation and by extension sUSD0 yield
Dual oracle system (ClassicalOracle + Chainlink); continuous monitoring with alert thresholds
Governance risk
DAO decisions affecting yield allocation, redemption fees, or vault parameters
On-chain voting via UIPs; transparent proposal process; fee cap at 3 bps
Counterparty risk
Failure of tokenizer, fund manager, custodian, or banking partner
Multi-provider diversification; regulated entities (BNY Mellon, CACEIS); rigorous due diligence framework
Regulatory risk
Evolving regulatory landscape for stablecoins and yield-bearing instruments
Multi-jurisdictional tokenizer diversification (CIMA, AMF, CFTC); no leverage; full backing
Security & Audits
sUSD0 is covered by the protocol-wide security program comprising 20+ independent audits since May 2024.
Hexens
sUSD0 and sEUR0 audit
Nov 2025
Spearbit
Yield Module audit
Feb 2025
Halborn
RDM (Revenue Distribution Module) audit
Nov 2025
Sherlock
Multiple audit campaigns covering protocol-wide modules
Nov 2024 -- Nov 2025
Bug Bounty: Active program via Sherlock Bug Bounties (audits.sherlock.xyz/bug-bounties). Triage and severity handled by Sherlock's security team.
Security contact: [email protected]
Quick Links
sUSD0 — Product Overview: https://docs.usual.money/usual-products/yield-products/usd-products/usd0-savings
Security & Audits: https://tech.usual.money/security-and-audits/audits
Contract Deployments: https://tech.usual.money/smart-contracts/contract-deployments
Etherscan — sUSD0: https://etherscan.io/token/0xd861bE82dEe3223CFBEd160791f6550b0704D406
Disclaimer
This factsheet is provided for informational purposes only and does not constitute investment advice, an offer to sell, or a solicitation of an offer to buy any security or financial instrument. sUSD0 is a decentralized protocol token governed by Usual DAO; participation involves risks including but not limited to smart contract risk, collateral risk, yield variability, and regulatory risk. Yields are variable and not guaranteed; past performance is not indicative of future results. The sUSD0 vault depends on protocol-level revenues, collateral performance, oracle and contract operations, and governance parameters. All smart contract addresses should be independently verified on the respective block explorers before interacting. Protocol parameters — including redemption fees, yield allocation rates, and governance structure — are subject to change through DAO governance.
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