fxUSD does not sit outside the trade. It is the debt that makes the trade possible. Long and short positions supply collateral and absorb rebalancing, the Stability Pool supplies inventory, keepers push the system back from its limits, and administrators still choose many of those limits.
The CoinGecko asset is Ethereum fxUSD at 0x085780…d8f6. V1, released in August 2023, wrapped stable legs produced by variable-leverage token pairs. Roughly 16 months later V2 kept the same stablecoin identity but rebuilt the leverage side around fixed-leverage xPOSITION; V2.1 added sPOSITION. rUSD stayed a separate 0x65D72…7D18 LRT product.
f(x) writes collateral value on one side and fxUSD plus leveraged-position value on the other. When a long is opened, collateral and flash liquidity can create an xPOSITION while fxUSD appears as debt. A short instead locks fxUSD and borrows exposure through the short-pool system.
That identity describes internal solvency. It does not say a bank holds one dollar, nor give fxUSD owners a legal claim on the f(x) Treasury. The actual holder path is the proxy contract’s supported-market redemption, oracle price and minimum-output rules.
Users can supply fxUSD or USDC to the V2 Stability Pool. The pool trades between them around the peg and is advertised as receiving collateral yield, position fees, Aave yield and FXN emissions. Each source is variable and governance-directed, so displayed APY is not a contractual coupon.
When a long approaches its rebalance line, a keeper uses fxUSD from the pool, burns part of the position debt and receives collateral that is sold back toward fxUSD or USDC. Pool depositors therefore fund the mechanism that earns their fees.
The “Liquidation Brake” targets a safer leverage level rather than closing a whole position at the first threshold. If that transaction fails or price moves further, hard liquidation closes the remaining debt. Leverage can still destroy position equity.
After that, the published waterfall uses a Reserve Fund. Any deficit it cannot cover is redistributed among surviving leveraged positions. At aggregate collateralization below 100%, operations may halt and protocol assets may be deployed for recapitalization.
This ordering protects fxUSD economically before leveraged claims, but “protect” is not “guarantee.” Keeper availability, DEX execution, collateral liquidity and the oracle all sit between the formula and the outcome.
FxUSDPriceOracle reads a Curve EMA and Chainlink USDC/USD, rejecting stale Chainlink updates. DEFAULT_ADMIN_ROLE can replace the Curve pool and change up-peg and depeg thresholds. PoolManager admins can register pools, alter capacities, rate providers, permissionless-liquidation thresholds and asset strategies.
EMERGENCY_ROLE can pause and unpause PoolManager. The official multisig page assigns technical and treasury operations to 0x26B2…BbF with a six-signature threshold and gives a separate emergency Safe pause authority.
Deployment records show fxUSD, its oracle and core managers behind proxy infrastructure, and published 2025–2026 upgrades reuse the fxUSD address. Audits cover named versions and components; they do not freeze admin choices or certify every later keeper call. The unresolved backing language—wstETH plus WBTC on the live page, solely stETH in its FAQ, stETH/frxETH in V1 docs—is why this dossier treats the live reserve set as an onchain question.
Variable-leverage token pairs produce stable legs that can be wrapped into fxUSD.
The audit index links the dedicated fxUSD report.
Fixed-leverage positions replace the V1 user model while fxUSD continues.
Secbit’s scope adds short-position logic to the audit trail.
The independent review covers leverage, stability, oracle and asset-management components.
The audit index lists Secbit’s review of EIP-3009 and base-token components. This records the reviewed scope, not activation of a cross-chain upgrade.
Last evidence review: 2026-09-05
fxUSD is the Ethereum stablecoin proxy at 0x085780…d8f6. In f(x) V2 it is minted as debt when users create collateralized long positions or fxMINT positions, while the Stability Pool also holds fxUSD and USDC for peg operations. rUSD, FXN, fxSAVE and xPOSITION are separate tokens or products with different claims.
f(x) tries to allocate one collateral portfolio between a dollar-like liability and traders who want amplified price exposure. That arrangement can improve capital use only if readers track the waterfall: which side absorbs volatility, who triggers rebalancing, when redemption stops, and which administrator can change the oracle, pools or implementation.
The invariant accounts for fxUSD plus long and short positions against wstETH/WBTC-related reserves. Keepers burn fxUSD debt and sell collateral to rebalance positions before liquidation. Stability Pool inventory swaps fxUSD and USDC around the peg and receives configured revenues. Oracle and PoolManager roles can alter thresholds, pool capacity and emergency state, while proxy admins can upgrade implementations.
No. fxUSD uses 0x085780…d8f6. rUSD uses 0x65D72…7D18 and was built around separate LRT reserve markets.
No bank-dollar covenant was found. The documented right is an onchain redemption at oracle value through supported markets, subject to contract state, fees, liquidity and minimum-output checks.
Position equity is rebalanced and may be liquidated; the Reserve Fund covers bad debt before uncovered amounts are redistributed across remaining leveraged positions under the published waterfall.
No. Rebalancing is intended to reduce leverage before the liquidation line, but the docs explicitly preserve hard liquidation if rebalancing fails.
DEFAULT_ADMIN_ROLE controls pools, capacities, rate sources, thresholds and asset allocations; EMERGENCY_ROLE can pause. ProxyAdmin infrastructure can replace implementations.
The live site names wstETH and WBTC, but another FAQ sentence says solely stETH and retained V1 pages mention stETH/frxETH legs. The precise live market set must be checked onchain.
Choose a tracking site for f(x) Protocol fxUSD:
