f(x) - fxSAVE
not rated yetf(x) Protocol (by AladdinDAO) is a DeFi platform on Ethereum that splits staked ETH collateral into fxUSD (a decentralized stablecoin) and xPOSITIONs (leveraged positions up to 7x on ETH/BTC). fxSAVE is the protocol's auto-compounding savings vault — an ERC-4626 wrapper around the V2 Stability Pool that earns yield from trading fees, liquidation premiums, and staking rewards.
How f(x) Protocol and fxSAVE work:
- f(x) mints fxUSD (pegged stablecoin) backed by wstETH and WBTC
- Traders open xPOSITIONs (up to 7x leverage on ETH/BTC) and pay protocol fees on every open/close
- The V2 Stability Pool holds fxUSD and USDC, acting as peg keeper and liquidation backstop
- fxSAVE deposits into the Stability Pool and auto-compounds all yield into a single token
- The vault is delta-neutral — not exposed to volatile asset price movements
- Yield comes from xPOSITION trading fees, reserve (ETH staking) yield, and liquidation/rebalancing proceeds — f(x) markets fxSAVE as emission-free
f(x) Protocol is developed by AladdinDAO. The protocol has been audited by OpenZeppelin and ChainSecurity. fxUSD circulating supply stands at ~$89M (October 2026).
Basic Information
Fundamentals
TVL
APR
Statistics
| Weekly | Monthly | Quarterly | Yearly | All-Time (Indexed) | |
|---|---|---|---|---|---|
Period Start | N/A | N/A | N/A | N/A | N/A |
| Period End (inclusive) | N/A | N/A | N/A | N/A | N/A |
| APR | N/A | N/A | N/A | N/A | N/A |
| APY | N/A | N/A | N/A | N/A | N/A |
CAGR | N/A | N/A | N/A | N/A | N/A |
Volatility | N/A | N/A | N/A | N/A | N/A |
Sharpe Ratio | N/A | N/A | N/A | N/A | N/A |
Sortino Ratio | N/A | N/A | N/A | N/A | N/A |
| TVL High | N/A | N/A | N/A | N/A | N/A |
| TVL Low | N/A | N/A | N/A | N/A | N/A |
Inflows | — | — | — | — | — |
Liquidity
Not calculated yet
Liquidity analysis will be available soon
Strategy
- Acquire fxUSD or USDC
- Purchase fxUSD on DEXs or mint it through the f(x) Protocol
- Alternatively, use USDC directly — fxSAVE accepts both
- fxUSD is a decentralized stablecoin backed by wstETH and WBTC
- Deposit into fxSAVE
- Navigate to the fxSAVE page and deposit fxUSD or USDC
- fxSAVE is an ERC-4626 tokenized vault — you receive fxSAVE tokens representing your share
- Your deposit enters the V2 Stability Pool which maintains fxUSD's peg
- Earn auto-compounded yield
- xPOSITION trading fees flow to the Stability Pool on every position open/close
- wstETH staking rewards from the protocol's collateral reserves add to yield
- Liquidation and rebalancing proceeds captured by the Stability Pool add to yield
- All yield is auto-compounded — the fxSAVE token value increases over time
- Withdraw anytime
- Redeem fxSAVE tokens back to fxUSD/USDC at the increased exchange rate
- The vault is delta-neutral — no volatile asset exposure to manage
Yield Source
fxSAVE generates yield from multiple real protocol revenue sources — all without relying on unsustainable token emissions or points incentives. Current and historical APY are shown in the live statistics on this page.
Primary yield sources:
- xPOSITION trading commissions: Every leveraged position (up to 7x on ETH/BTC) opened or closed incurs a protocol fee, which flows directly to the Stability Pool and fxSAVE holders
- ETH staking rewards: The protocol's wstETH collateral generates Lido staking yield, a portion of which is distributed to the Stability Pool
- No FXN emissions: f(x) describes fxSAVE's yield as fully organic — FXN emissions are not part of it, and protocol-wide FXN emissions are being cut on a fixed schedule (a further 10% cut in September 2026)
- Liquidation and rebalancing proceeds: When xPOSITIONs are rebalanced or liquidated, the Stability Pool captures value from these events
The yield flywheel:
- More trading activity on xPOSITIONs → more fees generated → higher fxSAVE yield
- Higher yield attracts more Stability Pool deposits → deeper liquidity for fxUSD peg → more confidence for traders
- The Stability Pool also acts as a peg keeper, buying fxUSD below peg and selling above peg
fxSAVE auto-compounds all these yield sources — wBTC and wstETH received from liquidations are automatically converted back into stablecoins and reinvested.
Strategy Limits
Deterministic Constraints
- Yield depends on xPOSITION trading volume — low trading activity reduces fee income
- Yield is fully organic — there are no FXN emissions to cushion periods of low trading activity
- Only available on Ethereum mainnet
- fxUSD peg target is maintained through economic incentives, not hard guarantees
Probabilistic Constraints
- In extreme market conditions, the rebalancing and liquidation mechanisms may fail, potentially creating bad debt
- Stability Pool deposits may temporarily convert to collateral (wstETH/WBTC) during liquidation events
- If total collateralization drops below 100%, new position creation halts, which could reduce fee generation
- fxUSD could depeg if collateral values crash beyond the protocol's protective mechanisms
Underlying Assets/Allocations
Risk Analysis
not rated yetPotential Risks
Based on the official f(x) Protocol documentation and audit reports, the following risks are associated with fxSAVE:
- Smart Contract Risk - Despite OpenZeppelin audit, a critical flash loan vulnerability was found post-audit by ChainSecurity; complex multi-protocol integrations increase attack surface
- Bad Debt Risk - In worst-case scenarios where both rebalancing and liquidation mechanisms fail, the protocol may incur bad debt affecting Stability Pool depositors
- fxUSD Depeg Risk - If collateral values (wstETH, WBTC) crash severely or liquidations fail, fxUSD could lose its dollar peg
- Collateral Conversion Risk - During liquidation events, Stability Pool deposits may temporarily convert to wstETH/WBTC, introducing brief volatile asset exposure
- Trading Volume Risk - fxSAVE yield heavily depends on xPOSITION trading activity; bear markets or low volatility could significantly reduce fee income
- Oracle Risk - The OpenZeppelin audit flagged price manipulation vulnerabilities in low-TVL pools and stale oracle values
- Share Inflation Risk - The audit identified a potential share inflation attack vector on the fxSAVE ERC-4626 wrapper
- Dependency Risk - Protocol integrates with Aave, Morpho, Curve, and Lido, inheriting risks from all dependencies
Risk Analysis (3rd Parties)
Summary
f(x) Protocol's fxSAVE vault offers a delta-neutral, auto-compounding stablecoin yield strategy powered by real protocol revenue from xPOSITION trading fees, ETH staking rewards, and liquidation proceeds. The protocol has been audited by OpenZeppelin and benefits from a reserve fund for extreme scenarios. However, a critical flash loan vulnerability was discovered post-audit by ChainSecurity (promptly patched, no funds lost), and only a fraction of audit findings were fully resolved. The protocol's complex design — integrating Aave, Morpho, Curve, and leveraged trading — creates a large attack surface. Users should weigh the yields against the protocol's complexity and history of security findings.
See the OpenZeppelin audit report: "f(x) v2 Audit"
OpenZeppelin Audit: The f(x) v2 contracts were audited by OpenZeppelin, covering core pool mechanisms, price oracle infrastructure, and asset management. The audit identified 1 critical, 2 high, 7 medium, and 13 low severity issues.
Delta-Neutral Design: The fxSAVE vault maintains delta-neutrality through the Stability Pool mechanism, meaning depositors are not directly exposed to ETH/BTC price volatility. The pool holds fxUSD and USDC, with collateral received from liquidations auto-compounded back to stablecoins.
Reserve Fund: The protocol allocates a portion of its revenue to a reserve fund to cover extreme scenarios where both rebalancing and liquidation mechanisms fail, providing an additional safety buffer.
See ChainSecurity's disclosure: "Circumventing Access Control with a Double Flash Loan Attack"
Critical Flash Loan Vulnerability (April 2025): ChainSecurity discovered a critical vulnerability that could allow attackers to steal collateral from user positions via nested flash loans, putting over $2M at risk. The f(x) team promptly removed the Balancer V2 flash loan integration to eliminate the attack vector. No funds were lost.
Partial Audit Resolution: The OpenZeppelin audit raised 23 issues plus 23 notes (46 findings), and only 5 were resolved at audit completion — all 3 critical/high issues and 2 of the 7 medium issues. The 13 low-severity issues and all notes were acknowledged for future updates or deemed low-impact.
Complex Protocol Design: f(x) Protocol uses advanced mechanisms (leverage ticks, flashloan-based leverage, multi-protocol composability with Aave/Morpho/Curve) which increase the attack surface. The flash loan vulnerability demonstrated how complex interactions can create unexpected exploit paths.