USDB (Bridge USD) — USDB is Bridge.xyz's tokenised representation of USD, used to settle balances inside the Bridge.xyz banking platform; each USDB is backed 1:1 by USD held at FDIC-insured partner banks.
USDB lets Bridge move balances on-chain (specifically Solana) at the speed of a blockchain transaction while keeping the underlying funds in regulated FDIC-insured custody.
For end users, USDB is invisible — you see "USD balance" in the Kronos app — but the underlying ledger uses USDB so balances can be paid out instantly via Bridge's rails.
Kronos USD balances are held as USDB on Solana via Bridge.xyz. End users see plain US dollars in the app; the on-chain USDB layer enables instant settlement and 24/7 movement. FDIC pass-through coverage flows through Bridge's partner banks.
It is conceptually similar (1:1 USD-backed) but operates inside Bridge's banking-rails ecosystem rather than as an open-market stablecoin.