sUSD is Synthetix's legacy synthetic US-dollar stablecoin, now being wound down and converted to vested SNX under governance proposal SIP-423.
Key Data
| Backing | Legacy SNX-collateralized synthetic dollar backed by the Synthetix debt pool. |
| Redemption | Under SIP-423, frozen legacy sUSD is redeemed at $1 of value in SNX on Ethereum, with a one-year lock and one-year vesting schedule. |
| Peg Currency | USD |
| Launched | 2018 |
Supported Networks
Depeg History
| Date | Low Price | Duration | Cause |
|---|---|---|---|
| 2025-03-31 | $0.9160 | — | Transition-period peg instability and excess sUSD supply pressure |
| 2025-04-28 | $0.7000 | — | Reported impact of the SIP-420 protocol shift, lower collateralization, and liquidity outflows |
Mint / Burn Mechanism
Historically minted against SNX staking via the shared debt pool; minting deprecated and legacy supply being converted to vested SNX under SIP-423.
Use Cases
Overview
sUSD is the legacy synthetic US-dollar stablecoin of the Synthetix protocol. It is being retired rather than actively expanded.
How It Works
Historically, sUSD was minted against SNX staking through the protocol's shared debt-pool accounting. Under SIP-423, legacy sUSD is frozen and holders are redeemed at one dollar of value in SNX, subject to a lock and vesting schedule.
Reserve Backing
sUSD was backed by SNX collateral and protocol debt accounting rather than fiat reserves. During 2025 it experienced significant peg instability before the retirement decision.
Supported Networks
sUSD exists on Ethereum and Optimism.
Recent Activity
- 2025-04-28DepegReported impact of the SIP-420 protocol shift, lower collateralization, and liquidity outflows
- 2025-03-31DepegTransition-period peg instability and excess sUSD supply pressure
Other USD Stablecoins
Profile compiled from issuer disclosures, regulatory filings, press releases, and financial media. Market and on-chain data sourced directly or via third-party providers. See methodology.