Fluid Lending Protocol
Score Breakdown
| Category | Weight | Score |
|---|---|---|
| Audits & Historical | 20% | 1.50 |
| Centralization & Control | 30% | 1.83 |
| Funds Management | 30% | 1.25 |
| Liquidity Risk | 15% | 2.00 |
| Operational Risk | 5% | 1.50 |
| Final Score | 1.1 / 5.0 | |
Minimal Risk
Overview
This assessment focuses on the Fluid Lending Protocol (fTokens) — an ERC4626-compliant lending product built on top of Fluid's unified Liquidity Layer. Users supply assets (USDC, USDT, WETH, wstETH, etc.) and receive fTokens representing their share of the lending pool. Yield is generated from borrower interest via the Vault Protocol.
Architecture dependency chain relevant to lending risk:
fTokens (Lending Protocol)
↓ deposits/withdraws via
Liquidity Layer (central fund store, 0x52Aa...)
↑ borrows against collateral
Vault Protocol (borrowers, liquidations, oracles)
fToken holders are exposed to risks across this entire stack: the Lending Protocol itself, the Liquidity Layer that holds all funds, and the Vault Protocol whose borrowers generate the yield. The DEX Protocol and stETH Protocol also interact with the Liquidity Layer but are secondary dependencies.
Fluid is governed by FLUID token holders via onchain GovernorBravo governance with a 1-day Timelock. The protocol was developed by Instadapp Labs and launched in February 2024.
Links:
Risk Summary
Key Strengths
- Lending-specific: ERC4626-compliant fTokens with monotonically increasing exchange rates, no admin ability to access funds
- Battle-tested team with ~6 years of DeFi operational history (Instadapp since 2019), zero security incidents
- 8 security audits from 4 reputable firms (PeckShield, StateMind, MixBytes, Cantina) — Lending Protocol directly covered in 2 of them, Liquidity Layer (critical dependency) covered in 4
- Onchain GovernorBravo governance with 1-day Timelock and 117 proposals executed — all core contracts owned by Timelock
- $1.28B lending TVL across 5 chains, ~2 years in production with zero incidents
- Active Immunefi bug bounty ($500K max) with Lending Protocol explicitly in scope
- Fully programmatic interest rates and exchange rates — no offchain oracle needed for lending
Key Risks
- Shared Liquidity Layer: fToken deposits are commingled in the Liquidity Layer with Vault, DEX, and stETH protocol funds. A vulnerability in any protocol on the stack affects fToken holders.
- Liquidity Layer upgradeability: Upgradeable proxy controlled by Timelock with only 1-day delay. Malicious upgrade could affect all deposited funds.
- Complex counterparty chain: fToken yield depends on Vault Protocol borrowers → liquidation mechanism → oracle system. Failure at any point could lead to bad debt.
- Concentration risk: wstUSR is 18.9% of all lending TVL. Top 5 assets = 57.6% of lending TVL.
- No formal verification (Certora, Halmos) has been performed
Critical Risks
- None identified that would trigger automatic score of 5. All contracts verified, reserves fully onchain, governance is via onchain GovernorBravo + Timelock. No EOA control. Guardian can only pause.
Full Report
Contract Addresses (Ethereum Mainnet)
All contracts verified on Etherscan. Compiled with Solidity 0.8.21.
fToken Contracts (Lending)
fToken On-Chain State (Ethereum Mainnet, as of Feb 2026)
| fToken | Total Assets | Exchange Rate | Supply Rate | Approx TVL |
|---|---|---|---|---|
| fUSDC | 274.8M USDC | 1.1853 | 4.59% | ~$274.8M |
| fUSDT | 167.5M USDT | 1.1788 | 3.99% | ~$167.5M |
| fGHO | 42.3M GHO | 1.0975 | 7.32% | ~$42.3M |
| fwstETH | 2,874 wstETH | 1.0381 | 0.26% | ~$8.9M |
| fUSDtb | 5.8M USDtb | 1.0171 | 1.82% | ~$5.8M |
| fWETH | 1,773 WETH | 1.0682 | 2.56% | ~$4.7M |
| fsUSDS | 15,025 sUSDS | 1.0021 | 0.00% | ~$15.8K |
| Total Ethereum fTokens | ~$504M |
All exchange rates are >1.0, confirming accumulated yield since launch. No rewards programs currently active on any fToken — yields are purely organic from supply/borrow spreads.
Core Infrastructure (Dependency for Lending)
- Liquidity Layer:
0x52Aa899454998Be5b000Ad077a46Bbe360F4e497— Central contract holding all funds. Upgradeable proxy (Instadapp Infinite Proxy) with AdminModule and UserModule. - LendingFactory:
0x54B91A0D94cb471F37f949c60F7Fa7935b551D03— Creates fToken markets. Owner: Timelock. - Timelock:
0x2386DC45AdDed673317eF068992F19421B481F4c— Owner of Liquidity Layer, LendingFactory, VaultFactory, DexFactory. 1-day delay. - GovernorBravo:
0x0204Cd037B2ec03605CFdFe482D8e257C765fA1B— Onchain governance. 117 proposals executed. - Avocado Multisig:
0x4F6F977aCDD1177DCD81aB83074855EcB9C2D49e— Timelock guardian (cancel-only). Also owns DeployerFactory. - FLUID Token:
0x6f40d4A6237C257fff2dB00FA0510DeEECd303eb— Governance token. 100M max supply, ~77.5M circulating.
Resolvers (Read-Only Periphery)
- FluidLiquidityResolver:
0xD7588F6c99605Ab274C211a0AFeC60947668A8Cb— Active resolver for supply/borrow rates, exchange prices, rate model params - RevenueResolver:
0x0A84741D50B4190B424f57425b09FAe60C330F32
Audits and Due Diligence Disclosures
Fluid has undergone 8 distinct security audits across 4 audit firms, covering all major protocol components. The Lending Protocol was covered in the PeckShield and StateMind full-protocol audits. The Liquidity Layer (critical dependency for lending) was audited by both MixBytes and StateMind in 2025 using a dual-audit approach. All audit reports are available on the audits and security page.
| # | Firm | Date | Scope | Critical | High | Medium | Low | Info | Total |
|---|---|---|---|---|---|---|---|---|---|
| 1 | PeckShield | Nov 2023 | Full Protocol (incl. Lending) | 0 | 4 | 4 | 5 | 0 | 13 |
| 2 | StateMind | Oct–Dec 2023 | Full Protocol (incl. Lending) | 3 | 8 | 15 | 0 | 40 | 66 |
| 3 | MixBytes | Mar–Jun 2024 | Vault Protocol | 0 | 0 | 2 | 4 | 0 | 6 |
| 4 | Cantina | Sep–Oct 2024 | DEX Protocol | 0 | 0 | 2 | 7 | 4 | 13 |
| 5 | MixBytes | Oct 2024 | DEX Protocol | 0 | 0 | 0 | 3 | 0 | 3 |
| 6 | MixBytes | Sep–Dec 2025 | Liquidity Layer | 0 | 0 | 0 | 2 | 0 | 2 |
| 7 | StateMind | Sep–Oct 2025 | Liquidity Layer | 0 | 1 | 0 | 0 | 4 | 5 |
| Total | 3 | 13 | 23 | 21 | 48 | 108 |
Lending-relevant audit details:
- PeckShield — Full Protocol (report): Covered lending/fToken contracts. All 13 issues resolved (12 resolved, 1 mitigated — "Trust Issue of Admin Keys").
- StateMind — Full Protocol (report): Covered Lending/iTokens (now fTokens), Liquidity Layer, Vaults, Oracles. Critical finding: LendingRewardRateModel returns rate with incorrect decimals (pool-draining risk) — fixed. Also: incorrect supplyExchangePrice calculation, DOS of iToken markets — all fixed.
- MixBytes — Liquidity Layer (report): Directly impacts lending withdrawal/supply mechanics. 2 Low findings.
- StateMind — Liquidity Layer Updates (report): 1 High: incorrect net transfer calculation causing user overpayment — fixed.
- MixBytes — Vault Protocol (report): Vault borrowers generate fToken yield. Relevant for lending counterparty risk. Insufficient reentrancy protection — fixed.
No formal verification (Certora, Halmos, etc.) has been performed.
Bug Bounty
Immunefi Bug Bounty Program — Active program under the "Instadapp" name. Last updated 2024-12-15. Fluid Lending Protocol is explicitly in scope.
| Category | Severity | Min Reward | Max Reward | Calculation |
|---|---|---|---|---|
| Smart Contract | Critical | $25,000 | $500,000 | 10% of directly affected funds |
| Smart Contract | High | $5,000 | $100,000 | 50% of affected funds value |
| Web/App | Critical | $5,000 | $50,000 | Range model |
| Web/App | High | $5,000 | $10,000 | Range model |
Fluid scope: Liquidity Layer, Lending Protocol, Vault Protocol (excluding periphery folder). Source repo.
Payment: USDC, USDT, or DAI on Ethereum. Medium/Low severity levels are not in scope.
Historical Track Record
- Production History: Fluid launched on Ethereum mainnet on February 20, 2024 (first TVL recorded). The protocol has been in production for approximately ~2 years (722 days as of February 2026).
- Lending TVL: $1.28B across all chains (88.7% of Fluid's total $1.45B TVL). Lending is the dominant product. TVL peaked at $2.68B (Oct 2025). TVL maintained >$500M for over 1.5 years.
- Multi-chain Lending Deployment:
| Chain | Lending Supply TVL | % of Lending | Borrowed | Utilization |
|---|---|---|---|---|
| Ethereum | $718.9M | 56.1% | $682.7M | 95.0% |
| Plasma | $366.9M | 28.6% | $279.3M | 76.1% |
| Arbitrum | $146.7M | 11.4% | $77.9M | 53.1% |
| Base | $43.2M | 3.4% | $20.0M | 46.3% |
| Polygon | $5.4M | 0.4% | $2.6M | 47.8% |
| Total | $1.28B | 100% | $1.06B | 82.9% |
- Incidents: No reported security incidents or exploits found. Not listed in DeFi Llama hacks database. No rekt.news entries for Fluid or Instadapp.
- TVL Stability: Only 1 daily drop >15% in entire history (August 6, 2024, -16.1%, aligned with broader crypto market selloff). Average daily volatility of 2.53% over past 90 days.
- Instadapp Legacy: Instadapp has been operating since 2019, maintaining ~$2B TVL through 2023. Fluid represents the team's most ambitious protocol built on years of DeFi infrastructure experience.
Funds Management
How fTokens Work
fTokens are ERC4626-compliant vault tokens. When a user deposits an underlying asset (e.g., USDC), the fToken contract:
- Calls
LIQUIDITY.operate()to deposit the underlying into the Liquidity Layer - The Liquidity Layer triggers a callback; the fToken transfers the underlying via SafeTransfer or Permit2
- Shares are minted to the user based on the current exchange rate
On withdrawal, the reverse occurs: shares are burned before the underlying is withdrawn from the Liquidity Layer (burn-first pattern for safety).
Exchange rate: Computed onchain as tokenExchangePrice / EXCHANGE_PRICES_PRECISION (1e12 precision). The rate is monotonically increasing — it can never decrease. It incorporates:
- Yield from the Liquidity Layer (borrower interest)
- Optional rewards from a
LendingRewardsRateModel(currently inactive for all fTokens; yields are purely organic)
Safety mechanisms in fToken contracts:
- Custom reentrancy guard (deposit/withdraw/rebalance all protected)
- Callback validation: checks caller = Liquidity AND token = ASSET AND status = ENTERED
- Burn-before-withdraw pattern
- BigMath precision with SafeCast overflow protection
- Rewards rate capped at 50% APR maximum
Accessibility
- Supplying: Permissionless — anyone can deposit via fTokens. No whitelist required.
- Redemption: fToken withdrawals via
withdraw()orredeem()(standard ERC4626). Subject to Liquidity Layer withdrawal limits. If utilization is very high, withdrawals may be temporarily throttled until limits expand or borrows are repaid. - Fees: No explicit deposit/withdrawal fees. Interest rates are algorithmically determined by utilization via a kink-based model.
Yield Source and Counterparty Risk
fToken yield comes from borrower interest. Borrowers use the Vault Protocol to deposit collateral and borrow assets from the Liquidity Layer. This means fToken holders are exposed to:
- Vault Protocol solvency: If borrowers default and liquidations fail to recover full value, bad debt could affect lending reserves
- Liquidation effectiveness: The tick-based liquidation mechanism must function correctly to prevent bad debt accumulation
- Oracle correctness: Vault liquidations depend on Chainlink, UniswapV3 TWAP, and Redstone price feeds. Oracle failures could delay liquidations
Collateral quality backing fToken yield (borrower collateral types):
- Blue-chip: ETH, WETH, wstETH, weETH, WBTC, cbBTC
- Stablecoins: USDC, USDT, sUSDe, GHO
- Others: PAXG, XAUt, various LSTs
Collateralization
- Backing: All lending positions are over-collateralized onchain. Borrowers must maintain collateral ratios (80-95% LTV depending on the pair).
- Liquidations: Fully onchain tick-based mechanism. Liquidation penalty as low as 0.1% for correlated pairs (wstETH/ETH), higher for uncorrelated pairs.
- Withdrawal Gap: Extra gap on Liquidity Layer limits reserved for liquidations to ensure they can always execute.
Provability
- Transparency: All reserves are fully onchain and verifiable via resolver contracts (FluidLiquidityResolver at
0xD7588F6c99605Ab274C211a0AFeC60947668A8Cb). - Exchange Rate: fToken exchange rates are computed programmatically onchain (ERC4626 standard). No offchain oracle or admin input needed. Rate is monotonically increasing.
- Interest Rates: Algorithmically determined based on utilization. USDC rate model: kink at 85% utilization (5.5% rate), second kink at 93% (8.5%), max rate 40%.
- Revenue: Protocol revenue is calculated and verifiable via the RevenueResolver contract.
Interest Rate Model (USDC example, verified onchain)
| Parameter | Value |
|---|---|
| Model Type | Kinked (V2) |
| Kink 1 | 85% utilization |
| Rate at Kink 1 | 5.50% |
| Kink 2 | 93% utilization |
| Rate at Kink 2 | 8.50% |
| Max Rate | 40.00% |
| Fee | 10% of spread |
Liquidity Risk
Lending-Specific Liquidity Concerns
fToken holders face liquidity risk from the shared Liquidity Layer architecture. The Liquidity Layer serves not only lending but also Vaults, DEX, and stETH protocols. This means:
- Shared pool: fToken withdrawals compete with all other withdrawal demand on the Liquidity Layer
- High utilization: Ethereum lending utilization is 95.0% (borrowing $682.7M of $718.9M supplied). Overall cross-chain lending utilization is 82.9%. This is very high.
- Withdrawal limits: The Liquidity Layer enforces per-token expandable withdrawal limits.
maxWithdraw()returns the minimum of: (1) the withdrawal limit at Liquidity, (2) actual liquid balance. If a large withdrawal exceeds the current expanded limit, users must wait for the limit to expand.
Exit Mechanisms
- Normal exit: Call
withdraw()orredeem()on fToken. Subject to available liquidity and withdrawal limits. - Secondary market: fTokens are ERC20 tokens and can be traded on secondary markets, though no significant DEX liquidity for fTokens was observed.
- Throttled exit: During high utilization, the expansion-rate mechanism throttles large withdrawals. This prevents bank runs but delays exit for large holders.
Lending TVL by Asset Type (Ethereum)
| Asset Type | TVL | % of Ethereum Lending |
|---|---|---|
| Stablecoins | $368.8M | 51.3% |
| ETH/LSTs | $265.1M | 36.9% |
| BTC tokens | $54.4M | 7.6% |
| Other (Gold, FLUID, etc.) | $30.7M | 4.3% |
| Total | $718.9M | 100% |
Top Supply Assets (All Chains)
| Rank | Token | Supply TVL | % of Total |
|---|---|---|---|
| 1 | wstUSR | $242.5M | 18.9% |
| 2 | wstETH | $130.3M | 10.2% |
| 3 | USDT0 | $125.3M | 9.8% |
| 4 | USDC | $124.4M | 9.7% |
| 5 | weETH | $113.1M | 8.8% |
| 6 | sUSDe | $103.8M | 8.1% |
| 7 | USDT | $77.7M | 6.1% |
| 8 | WBTC | $55.1M | 4.3% |
| 9 | syrupUSDC | $51.3M | 4.0% |
| 10 | syrupUSDT | $51.0M | 4.0% |
Concentration risk: wstUSR is the single largest supply asset at 18.9% of total lending TVL. Top 5 assets account for 57.6%.
Historical Liquidity Performance
- During the August 2024 market stress (only >15% TVL drop), the protocol maintained operations normally. TVL recovered and continued growing.
- No recorded instances of withdrawal limit throttling causing prolonged user lockouts.
Centralization & Control Risks
Governance
- Governance Model: Onchain GovernorBravo governance. FLUID token holders vote on proposals that execute through a timelock. Discussion on governance forum, onchain voting via GovernorBravo, and offchain signaling via Snapshot.
- Timelock:
0x2386DC45AdDed673317eF068992F19421B481F4c— 1-day (86,400s) delay. Admin of GovernorBravo is the Timelock itself (standard circular pattern). The Timelock guardian is the Avocado multisig (can cancel queued transactions). Min delay: 1 hour, max delay: 30 days. - Owner/Admin: All core contracts (Liquidity Layer proxy admin, LendingFactory, VaultFactory, DexFactory) are owned by the Timelock (
0x2386DC45...), not directly by the multisig. Verified onchain viaowner()calls and EIP-1967 admin slot reads. - GovernorBravo Parameters (verified onchain):
- Quorum: 4,000,000 FLUID (4% of total supply)
- Proposal threshold: 1,000,000 FLUID (1% of total supply)
- Voting delay: 7,200 blocks (~1 day)
- Voting period: 14,400 blocks (~2 days)
- Proposals executed: 117
- Minimum time from proposal to execution: ~4 days (1d delay + 2d voting + 1d timelock)
Lending-Specific Admin Controls
| Role | Who | What They Can Do to Lending |
|---|---|---|
| Timelock (governance) | 0x2386DC45... |
Upgrade Liquidity Layer implementation, change LendingFactory owner, change supply/borrow configs, change rate models |
| LendingFactory Auths | Set by Timelock | Update fToken rewards config, change rebalancer address, rescue stuck tokens, set fToken creation code |
| LendingFactory Deployers | Set by Timelock | Create new fToken contracts |
| Rebalancer | 0x724d...b9b6 (fUSDC/fUSDT only) |
Deposit underlying without minting shares (adds as rewards). Cannot withdraw. |
| Guardian (Avocado multisig) | 0x4F6F977a... |
Pause Class 0 protocols only. Cannot move or withdraw funds. Cancel timelock transactions. |
Key finding: No admin role can directly access or move user funds deposited via fTokens. The most powerful action is the Timelock upgrading the Liquidity Layer implementation (1-day delay).
Programmability
- System Operations: Largely programmatic. Interest rates and exchange rates are all computed onchain algorithmically.
- Oracle System (dependency via Vault Protocol): Chainlink primary, with UniswapV3 TWAP, Redstone, and custom center-price oracles as fallbacks. Modular per vault.
- Rate Model: Interest rates determined algorithmically via kink-based utilization model. Parameters set by governance.
- Keepers/Automation: No keepers needed for lending. Liquidations (in Vaults) are incentivized and performed by external liquidators.
External Dependencies
- Liquidity Layer: Critical dependency — holds all fToken deposits. Upgradeable proxy controlled by Timelock.
- Vault Protocol: Generates fToken yield. Vault borrowers, liquidations, and oracles all affect lending counterparty risk.
- Chainlink: Indirect dependency via Vault Protocol oracle system. Multiple fallback oracle paths reduce risk.
- Permit2: Supported for deposits (Uniswap's
0x000000000022D473030F116dDEE9F6B43aC78BA3).
Operational Risk
- Team: Instadapp Labs. Founded by Sowmay Jain and Samyak Jain — both are publicly known, India-based founders active since 2019. Key GitHub contributors include thrilok209, KABBOUCHI, and SamarendraGouda.
- Funding: Well-funded by top-tier VCs: Pantera Capital, Coinbase Ventures, Standard Crypto, additional undisclosed investors.
- Legal Structure: Instadapp Labs. No formal DAO legal wrapper disclosed.
- Documentation: Comprehensive technical documentation at docs.fluid.instadapp.io. Full source code on GitHub.
- Communication: Active governance forum, Discord, Twitter @0xfluid, Blog.
- Incident Response: No documented formal incident response plan found. However, Guardian role can pause protocols immediately. Team has ~6 years of operational history with zero security incidents.
Monitoring
Contracts to Monitor
| Contract | Address | Why Monitor |
|---|---|---|
| fUSDC | 0x9Fb7b4477576Fe5B32be4C1843aFB1e55F251B33 |
Largest fToken (~$274.8M). Exchange rate, deposits/withdrawals |
| fUSDT | 0x5C20B550819128074FD538Edf79791733ccEdd18 |
Second largest (~$167.5M). Exchange rate, deposits/withdrawals |
| Liquidity Layer | 0x52Aa899454998Be5b000Ad077a46Bbe360F4e497 |
Holds all fToken deposits. Admin changes, implementation upgrades |
| Timelock | 0x2386DC45AdDed673317eF068992F19421B481F4c |
Owner of all core contracts — queued/executed transactions |
| GovernorBravo | 0x0204Cd037B2ec03605CFdFe482D8e257C765fA1B |
Governance proposals, voting, execution |
Key Events to Watch
| Contract | Event | Significance |
|---|---|---|
| Timelock | QueueTransaction / ExecuteTransaction |
Governance actions queued/executed — 1 day warning |
| Timelock | CancelTransaction |
Guardian cancelled a queued action |
| Liquidity Layer | LogUpdateAuth |
Auth permissions changed — affects who can modify lending configs |
| Liquidity Layer | LogUpdateGuardian |
Guardian address changed |
| Liquidity Layer | LogPauseUser / LogUnpauseUser |
Protocol paused/unpaused — directly affects fToken operations |
| Liquidity Layer | LogUpdateUserSupplyConfigs |
Supply limits changed — affects max fToken deposits |
| Liquidity Layer | LogUpdateUserBorrowConfigs |
Borrow limits changed — affects utilization and withdrawal availability |
| Liquidity Layer | LogUpdateRateDataV1 / LogUpdateRateDataV2 |
Interest rate parameters changed — affects fToken yield |
| LendingFactory | New fToken creation | New lending market created |
Reassessment Triggers
- Time-based: Reassess in 6 months (August 2026) — protocol will have >2.5 years history. Apply >2 year modifier (-0.5) at that time.
- Utilization-based: Reassess if Ethereum utilization exceeds 99% (negative — withdrawal availability critically constrained)
- TVL-based: Reassess if lending TVL changes by more than 50%
- Incident-based: Reassess after any exploit, governance change, or significant parameter modification
- Governance: Reassess if GovernorBravo parameters change (quorum, timelock delay, voting period) or if Avocado multisig signers change
- Dependency: Reassess if Liquidity Layer implementation is upgraded or if a new protocol is added to the shared liquidity pool