How Basalt works

How it works

USDb is a dollar unit. Approved counterparties mint it by paying USDC to the Minter, at a rate the desk quotes and signs; the USDC goes to the Treasury Safe. They redeem it through the Redeemer, which burns the USDb and pays USDC from a redemption reserve. USDb itself earns nothing.

sUSDb is an ERC-4626 vault over USDb. Every business day at 09:00 CET the NAV engine values the book, signs a report, and mints the yield earned on staked USDb into the vault. The number of shares does not change; what each share is worth does.

Fees

A performance fee of 10% is taken from yield, and only from yield that lifts the share price above its previous high. After a loss, no fee is charged until the price has recovered. There is no management fee, no deposit fee and no withdrawal fee. Minting and redeeming may carry a spread, shown in the quote before you accept it.

APY formula

P is the share price, net of the performance fee. When there are fewer than N days of history, the longest available period is used and shown next to the figure. An annualised figure is never shown without the period it is based on.

Withdrawals

Withdrawals go through a queue. When you request one, your shares are burned and their value is locked at the current price. After a notice period of seven days, you claim the USDb. The locked value stops earning yield, and it shares in any loss recognised during the notice period, so nobody can leave a known loss to those who stay. Claims cannot be stopped by the guardian alone.

Security

Every contract that holds or moves value is pausable. Upgrades and parameter changes wait 48 hours in a public timelock. A separate guardian Safe can pause and cancel pending operations, but cannot move value; replacing the guardian waits 14 days, longer than the notice period, so holders can leave first. Yield minted per update is capped, orders are bound to a rate range around par, and minting and redeeming have per-block, per-day and per-counterparty limits.

Audits: none completed yet. Two independent audits, a public contest and a bug bounty are required before mainnet. Every report will be published on the transparency page.

Risk

The yield comes from lending. If a borrower defaults and the collateral does not cover the loan, the loss is recognised on chain and the share price falls. Liquidity depends on loan maturities: the waterfall on the transparency page shows how much of the book can be turned into USDC within each horizon. Smart contracts can have bugs despite testing and audits. Nothing here is investment advice.

Contracts and addresses

The full list, with implementations, roles and parameters, is on the transparency page.