Usual Protocol USD0++ is a DeFi product within the Usual ecosystem built around USD0, a stablecoin backed by real-world assets. USD0++ was originally designed as a liquid bond version of USD0: users locked USD0 and received a transferable token that generated rewards in USUAL. In November 2025, under the UIP-12 proposal, the product was renamed bUSD0 (Bond USD0), making USD0++ its legacy name. The updated model separates the bond position from the early redemption right while preserving 1:1 redemption into USD0 at maturity.
Contents
- What Is Usual Protocol USD0++ and Why Did It Become bUSD0?
- How USD0, USD0++ and the Yield Mechanism Work
- USD0++ and bUSD0: Issuance, Redemption and Early Exit
- Using bUSD0 in DeFi and the Usual Ecosystem
- Risks and Prospects of Usual Protocol USD0++
1. What Is Usual Protocol USD0++ and Why Did It Become bUSD0?
Usual is a protocol for issuing stablecoins backed by tokenized real-world assets, or RWAs. The ecosystem's core dollar-denominated asset is USD0, an ERC-20 stablecoin pegged to the US dollar. Its backing primarily consists of short-term US Treasury securities, reverse repo instruments, and equivalent sovereign assets represented on-chain through regulated tokenized asset providers.
USD0++ emerged as a yield-bearing version of USD0. Instead of holding a freely redeemable stablecoin, users received a liquid bond position: the underlying USD0 was locked for a defined period, while USD0++ remained transferable and could be used across DeFi. Yield on the position was primarily distributed in USUAL tokens, connecting holders to the protocol's economic model.
In November 2025, the Usual DAO approved UIP-12, after which USD0++ was renamed bUSD0. The change was more than a rebranding: the new architecture introduced a separate early redemption right token called rt-bUSD0. Existing USD0++ positions were automatically migrated to bUSD0, which is why current Usual documentation uses the new name.
The current bUSD0 series matures on June 11, 2028. At maturity, each bUSD0 can be redeemed for one USD0 without requiring an additional redemption token. Structurally, this makes the product closer to a tokenized bond position than to a conventional yield-bearing stablecoin.
2. How USD0, USD0++ and the Yield Mechanism Work
USD0 remains the foundation of the system. Under the Usual model, it is fully backed by short-term government debt instruments and equivalent assets. The protocol uses infrastructure from tokenized collateral providers such as Hashnote, M^0, and Spiko. The collateral portfolio is subject to restrictions related to duration, credit risk, and currency exposure.
USD0 can be issued directly by depositing eligible RWAs or indirectly through USDC with the participation of a collateral provider. This structure separates the liquid base stablecoin from yield products built on top of it. bUSD0, formerly USD0++, is one of these products.
- USD0. The base dollar stablecoin backed by RWAs and designed for liquid use across DeFi.
- bUSD0 (USD0++). A bond token representing a locked position in USD0.
- rt-bUSD0. A separate right to redeem bUSD0 at par before maturity.
- USUAL. The protocol's governance and economic coordination token, used to pay daily bUSD0 coupons.
- USUALx. The staked version of USUAL used to participate in the distribution of a portion of protocol revenue.
bUSD0 yield is not generated by automatically increasing the holder's USD0 balance. Instead, holders receive daily coupons in USUAL. Following changes to the issuance model under UIP-11, USUAL distribution was limited through fixed quotas. As a result, the actual dollar-denominated return depends not only on the number of tokens received but also on the market value of USUAL.
3. USD0++ and bUSD0: Issuance, Redemption and Early Exit
Following UIP-12, primary issuance uses a two-token structure. When depositing one USD0, a user receives one bUSD0 and one rt-bUSD0. The first represents the main bond position and receives USUAL coupons, while the second represents the right to redeem the locked USD0 before maturity.
Before maturity, a user can combine 1 bUSD0 with 1 rt-bUSD0 to receive 1 USD0. Both tokens are redeemed in the process. Because rt-bUSD0 is a separate transferable asset, holders can sell their early redemption rights or purchase rt-bUSD0 on the secondary market if they need to close a position before maturity.
| Parameter | USD0 | bUSD0 (formerly USD0++) | rt-bUSD0 |
|---|---|---|---|
| Type | Stablecoin | Liquid bond token | Early redemption right |
| Underlying Asset | Tokenized RWAs | Locked USD0 | Right to unlock USD0 |
| Yield | Not the token's primary function | Daily USUAL coupons | No yield |
| Transferable | Yes | Yes | Yes |
| Redemption | 1:1 through the protocol mechanism | 1:1 into USD0 at maturity | Used together with bUSD0 for early redemption |
| Current Series Maturity | None | June 11, 2028 | Linked to bUSD0 maturity |
Another exit option is to sell bUSD0 on the secondary market. Before maturity, its market price does not have to remain constantly equal to one dollar or one USD0. In 2025, USD0++ experienced a period of significant discounting, after which the DAO adjusted the parameters of its early exit mechanism. In April 2025, UIP-6 increased the protocol-defined floor price from 0.87 to 0.92 USD0.
When held until June 11, 2028, rt-bUSD0 is no longer required: bUSD0 can be redeemed at par for USD0 on a 1:1 basis. The difference between the bond token's secondary-market price and its future redemption value can therefore represent another source of potential return for buyers who acquire bUSD0 at a discount.
4. Using bUSD0 in DeFi and the Usual Ecosystem
One of the defining features of USD0++ since its launch has been the liquidity of the position. Locking the underlying USD0 does not necessarily prevent holders from using their capital elsewhere: bUSD0 is an ERC-20 token that can be transferred between addresses and integrated with external DeFi protocols.
Current Usual documentation lists integrations for bUSD0 with platforms such as Pendle, Morpho, Curve, Aave, and other DeFi services. Depending on the specific integration, the token can be used for yield trading, liquidity provision, collateral, or more complex strategies. However, each additional integration introduces its own smart contract and liquidity risks.
On Pendle, the bond position can be separated into components associated with principal value and future yield. In lending markets, bUSD0 may be used as collateral, while trading pools provide secondary liquidity between bUSD0 and other assets. This composability distinguishes the product from a traditional bond, which typically exists outside open DeFi infrastructure.
Usual also develops dedicated Vaults for strategies involving bUSD0. Their purpose is to deploy the bond token in managed DeFi strategies while preserving the underlying USUAL coupons. Potential additional yield, however, comes with additional risks related to external protocols, strategy design, curators, and withdrawal conditions.
5. Risks and Prospects of Usual Protocol USD0++
The primary risk of bUSD0 is that its market value can differ from its face value before maturity. The period of USD0++ volatility in January 2025 demonstrated that a liquid bond token should not be treated as equivalent to a stablecoin that consistently trades at $1. For an early exit, users depend on rt-bUSD0, secondary-market liquidity, or the protocol's applicable floor-price mechanism.
Another factor is the yield structure. Coupons are paid in USUAL, meaning a high nominal token-denominated rate does not guarantee an equivalent dollar-denominated return. A decline in the price of USUAL reduces the real market value of rewards, while DAO decisions may affect future issuance and distribution parameters.
USD0 also carries underlying risks related to smart contracts, oracles, liquidity, tokenized RWA providers, custody infrastructure, and regulation. Usual reports more than 20 audits and applies collateral restrictions, including short-duration requirements and limits on credit and currency risks. Nevertheless, audits and government securities held in reserve do not completely eliminate technical or counterparty risks.
The evolution of USD0++ into bUSD0 illustrates how Usual is attempting to bring a bond-like structure into an open DeFi environment. Separating the position from the early redemption right makes the architecture more explicit: bUSD0 represents locked capital and future coupons, while rt-bUSD0 provides the right to access liquidity before maturity. For users, key factors include the price of bUSD0 relative to par, the cost of rt-bUSD0, the market value of USUAL, secondary-market liquidity, and the reliability of USD0 collateral. As a result, Usual Protocol USD0++ is now more accurately understood through its current bUSD0 structure: a tokenized bond position built on top of an RWA-backed stablecoin rather than a conventional yield-bearing stablecoin.
