Yearn — yvUSDC-1

Contract Addresses

Core yvUSDC-1 Contracts

Contract	Address	Type
yvUSDC-1 Vault	0xBe53A109B494E5c9f97b9Cd39Fe969BE68BF6204	Yearn V3 Vault (v3.0.2), Vyper minimal proxy
Accountant	0x5A74Cb32D36f2f517DB6f7b0A0591e09b22cDE69	Yearn Accountant (0% mgmt, 10% perf)
Fee Recipient (Dumper)	0x590Dd9399bB53f1085097399C3265C7137c1C4Cf	Claims fees and routes to auctions/splitters

Governance Contracts

Contract	Address	Configuration
Yearn V3 Role Manager	0xb3bd6B2E61753C311EFbCF0111f75D29706D9a41	Standard Yearn Role Manager, manages 37 vaults
Daddy / ySafe (Governance)	0xFEB4acf3df3cDEA7399794D0869ef76A6EfAff52	6-of-9 Gnosis Safe — ALL 14 vault roles
Brain (Operations)	0x16388463d60FFE0661Cf7F1f31a7D658aC790ff7	3-of-8 Gnosis Safe — QUEUE, REPORTING, DEBT, DEPOSIT_LIMIT, EMERGENCY
Security	0xe5e2Baf96198c56380dDD5E992D7d1ADa0e989c0	4-of-7 Gnosis Safe — manages via Role Manager
Strategy Manager (Timelock)	0x88Ba032be87d5EF1fbE87336b7090767F367BF73	TimelockController — 7-day delay for strategy additions. Self-governed: timelock holds TIMELOCK_ADMIN_ROLE, so config changes must go through 7-day delay
Keeper	0x604e586F17cE106B64185A7a0d2c1Da5bAce711E	yHaaSRelayer — REPORTING only
Debt Allocator	0x1e9eB053228B1156831759401dE0E115356b8671	Minimal proxy — REPORTING + DEBT_MANAGER

Yearn V3 Infrastructure

Contract	Address
Vault Factory (v3.0.2)	0x444045c5c13c246e117ed36437303cac8e250ab0
Tokenized Strategy	0xD377919FA87120584B21279a491F82D5265A139c

Active Strategies (3 in default queue, 2 with debt)

#	Strategy	Name	Current Debt (USDC)	Allocation
1	0x39c0aEc5738ED939876245224aFc7E09C8480a52	USDC to USDS Depositor	0	0%
2	0x25f893276544d86a82b1ce407182836F45cb6673	Spark USDC Lender	851,043.79	2.85%
3	0x7130570BCEfCedBe9d15B5b11A33006156460f8f	USDC to sUSDS Lender	28,988,516.09	97.15%

Previously queued, now revoked (activation = 0 at block 25073237):

• Morpho Gauntlet USDC Prime Compounder (0x694E47AFD14A64661a04eee674FB331bCDEF3737)
• Morpho Steakhouse USDC Compounder (0x074134A2784F4F66b6ceD6f68849382990Ff3215)
• Morpho OEV-boosted USDC Compounder (0x888239Ffa9a0613F9142C808aA9F7d1948a14f75)
• Morpho Yearn USDC Compounder (0xf1784A1bF0cBDE0F868838Dd093E65215343c4C0)
• USDC Fluid Lender (0x00C8a649C9837523ebb406Ceb17a6378Ab5C74cF)
• Aave V3 Lido USDC Lender (0x522478B54046aB7197880F2626b74a96d45B9B02)
• Aave V3 USDC Lender (0x694cdD19EBee7A974BA8fE3AF8B383bb256F2858)

Note: The Morpho Yearn USDC Compounder added on 2026-04-30 — which had been queued at 0 debt at the May 5 snapshot as a potential non-Sky re-diversification leg — has been revoked between May 5 and May 11. The queue is now down to 3 strategies (from 4), all Sky / Sky sub-DAO. Funded debt remains consolidated into a single Sky-governed venue (sUSDS Lender ~97%) plus a small Spark Lend slice (~3%). Active portfolio management continues; the vault has used Aave V3, Compound V3, Morpho, Spark, Fluid, and Sky strategies over its ~14-month lifetime.

Score impact of recent rebalancing: The vault remains ~100% Sky-governance-coupled (97% sUSDS Lender + 3% Spark Lender, both Sky / Sky sub-DAO). With the Morpho Yearn USDC Compounder now revoked, the optional non-Sky re-diversification leg that existed at May 5 has been removed. This is reflected in the Centralization → Dependencies subscore below.

Strategy Protocol Dependencies (current allocation)

Protocol	Strategy	Allocation	Notes
Sky / sUSDS	USDC to sUSDS Lender	97.15%	Sky Savings Rate via sUSDS — Sky-governed
Spark Lend (Sky sub-DAO)	Spark USDC Lender	2.85%	Sky sub-DAO; Spark admin keys live under Sky governance
Sky (yvUSDS via Depositor)	USDC to USDS Depositor	0% (queued)	Previously the dominant strategy; currently unfunded

Audits and Due Diligence Disclosures

Yearn V3 Core Audits

The underlying vault infrastructure has been audited by 3 reputable firms:

Auditor	Date	Scope	Report
Statemind	May 2, 2024	V3 Vaults (v3.0.0)	PDF
ChainSecurity	May 4, 2024	V3 Vaults + Tokenized Strategy (v3.0.0)	2 PDFs
yAcademy	Jun 2024	V3 Vaults (v3.0.1)	PDF

Sky/MakerDAO Audits (Underlying Protocol)

Sky (formerly MakerDAO) is one of the most extensively audited DeFi protocols:

Auditor	Coverage	Notes
ChainSecurity	9 audits covering USDS, sUSDS, Endgame Toolkit, LockStake, VoteDelegate	Core security partner
Cantina	10 audit reports including sUSDS (Sep 2024) and USDS (Jul 2024)	Comprehensive coverage
Sherlock	Public audit contest (Aug 2024)	Community audit
Trail of Bits	Core DAI system (legacy MCD)	Historical audit
PeckShield	Core DAI system (legacy MCD)	Historical audit
Quantstamp	Liquidations 2.0	Historical audit
ABDK	Vote Delegate security	Governance audit

LitePSM (used for USDC → DAI conversion): Audited by both ChainSecurity and Cantina.

Strategy Review Process

All strategies go through Yearn's formal 12-metric risk scoring framework (RISK_FRAMEWORK.md), covering:

• Strategy scores: Review level (ySec security review), testing coverage (95%+ for score 1), complexity (sLOC), risk exposure, centralization risk, protocol integration count
• External protocol scores: Audit count, centralization, TVL, longevity, protocol type

Bug Bounty

• Yearn (Immunefi): Active bug bounty. Max payout: $200,000 (Critical). Scope includes V3 vaults. 40 smart contracts in scope. Median resolution: 18 hours
  • Link: https://immunefi.com/bounty/yearnfinance/
• Yearn (Sherlock): Also listed: https://audits.sherlock.xyz/bug-bounties/30
• Sky/MakerDAO (Immunefi): Active bug bounty. Max payout: $10,000,000 (Critical). Scope includes DAI, USDS, sUSDS, PSM, and all core contracts
  • Link: https://immunefi.com/bug-bounty/sky/
• Safe Harbor: Yearn is not listed on the SEAL Safe Harbor registry

On-Chain Complexity

The yvUSDC-1 system is low complexity:

• 2 funded strategies on a single chain (Ethereum), both Sky-governed: sUSDS Lender (~97%) and Spark USDC Lender (~3%)
• Simple pipelines: sUSDS Lender: USDC → DAI → USDS → sUSDS (three 1:1 conversions + deposit). Spark USDC Lender: direct USDC supply to Spark Lend's USDC market
• No leverage, no looping, no cross-chain bridging
• Standard ERC-4626 deposit/withdrawal
• Blue-chip dependencies (Sky / Sky sub-DAO at ~100% of funded debt)
• Vault is immutable (non-upgradeable Vyper minimal proxy)

Historical Track Record

• Vault deployed: March 12, 2024 (block 19,419,991) — ~14 months in production
• TVL: 29,839,559.89 USDC (~$29.84M) — well within the $50M deposit limit
• PPS trend: 1.000000 → 1.105559 (~10.6% cumulative return, ~8.8% annualized)
• Security incidents: None known for this vault or Yearn V3 generally
• Strategy changes: active portfolio management. The vault has used Aave V3, Compound V3, Morpho, Spark, Fluid, and Sky strategies over its lifetime. Between the April 3 and May 5 snapshots: three Morpho compounders (Gauntlet, Steakhouse, OEV-boosted) revoked; Morpho Yearn USDC Compounder added 2026-04-30 (queued at 0 debt); funded debt consolidated into the sUSDS Lender + Spark. Between May 5 and May 11: the Morpho Yearn USDC Compounder was revoked (queue trimmed from 4 → 3)
• Current allocation: ~97% USDC to sUSDS Lender (Sky-governed) and ~3% Spark USDC Lender (Sky sub-DAO) — effectively single-ecosystem (Sky) at the snapshot
• Yearn V3 track record: V3 framework has been live since May 2024 (~24 months). No V3 vault exploits

Yearn protocol TVL: ~$197.5M total across all chains (DeFiLlama, April 2026).

Sky/sUSDS track record:

• sUSDS launched as part of Sky Endgame (2024)
• TVL: ~$5.38B+ in sUSDS (within ~$10B+ total USDS ecosystem)
• No security incidents since launch
• Sky Savings Rate (SSR): currently ~4.0% APY, set by Sky Governance
• Revenue sourced from over-collateralized loans and tokenized Treasury bill (RWA) investments

Funds Management

yvUSDC-1 deploys deposited USDC into yield strategies with 100% capital utilization. At the May 11 snapshot debt is concentrated in two Sky-governed strategies: USDC to sUSDS Lender (~97%) and Spark USDC Lender (~3%). One further strategy sits in the queue at 0 debt: USDC to USDS Depositor.

Strategy 1: USDC to USDS Depositor (0% — queued, unfunded)

Contract: 0x39c0aEc5738ED939876245224aFc7E09C8480a52

Conversion pipeline:

1. USDC → DAI via MakerDAO PSM Lite (0xf6e72Db5454dd049d0788e411b06CfAF16853042) — 1:1 at 0% fee (both tin and tout set to 0)
2. DAI → USDS via Sky DAI-USDS Exchanger (0x3225737a9Bbb6473CB4a45b7244ACa2BeFdB276A) — 1:1, no fee
3. USDS → yvUSDS via a Yearn V3 ERC-4626 vault — earns yield from the underlying yvUSDS vault strategies

Withdrawal pipeline: Reverse path (yvUSDS → USDS → DAI → USDC). If PSM tout fee exceeds 0.05%, the strategy falls back to Uniswap V3 swap with 0.5% slippage tolerance.

Strategy parameters:

• Deposit limit: 100,000,000 USDC
• Max acceptable PSM fee: 0.05% (falls back to Uniswap V3 if exceeded)
• Management: Brain multisig (3-of-8)
• Keeper: yHaaSRelayer (0x604e586F17cE106B64185A7a0d2c1Da5bAce711E)

Strategy 2: USDC to sUSDS Lender (~97.2% allocation)

Contract: 0x7130570BCEfCedBe9d15B5b11A33006156460f8f

Conversion pipeline:

1. USDC → DAI via MakerDAO PSM Lite — 1:1 at 0% fee
2. DAI → USDS via Sky DAI-USDS Exchanger — 1:1, no fee
3. USDS → sUSDS via Sky Savings vault (0xa3931d71877C0E7a3148CB7Eb4463524FEc27fbD) — earns the SSR (~4.0% APY)

Withdrawal pipeline: Reverse path (sUSDS → USDS → DAI → USDC). Same PSM fee fallback to Uniswap V3.

Strategy parameters: Same as USDS Depositor (100M deposit limit, 0.05% max PSM fee, Brain multisig management)

Strategy 3: Spark USDC Lender (~2.9% allocation)

Contract: 0x25f893276544d86a82b1ce407182836F45cb6673

Pipeline: Direct USDC supply to Spark Lend's USDC market. Spark Lend is a Sky sub-DAO governed by Sky / Spark governance — the underlying liquidity is Sky-administered.

Strategy parameters: Brain multisig management, keeper-driven reporting, ERC-4626 throughout.

Revoked strategies (historical context)

Three Morpho compounders that were active at the prior April 3 assessment have been revoked between snapshots: Morpho Gauntlet USDC Prime Compounder, Morpho Steakhouse USDC Compounder, and Morpho OEV-boosted USDC Compounder. The Morpho Yearn USDC Compounder (0xf1784A1bF0cBDE0F868838Dd093E65215343c4C0) — added on 2026-04-30 and queued at 0 debt at the May 5 snapshot as a potential non-Sky re-diversification leg — has also been revoked between May 5 and May 11 (activation = 0 at block 25073237). All four show activation = 0 at block 25073237. The cleanup also removed USDC Fluid Lender, Aave V3 Lido USDC Lender, and Aave V3 USDC Lender from the queue (also activation = 0). Per the broader cleanup pattern observed across the Yearn V3 risk-1 vaults in late April / early May, the team has been pruning the queue and consolidating debt. Independent attribution of the rationale has not been verified.

Accessibility

• Deposits: Permissionless — anyone can deposit USDC and receive yvUSDC-1 (ERC-4626 standard). Subject to $50M deposit limit
• Withdrawals: ERC-4626 standard. Users redeem yvUSDC-1 for USDC. For the sUSDS Lender: unwinds sUSDS → USDS → DAI → USDC pipeline. For Spark Lender: direct withdrawal from Spark Lend's USDC market. Both paths are highly liquid
• No cooldown or lock period — unlike yvUSD's LockedyvUSD wrapper
• Fees: 0% management fee, 10% performance fee (taken via accountant during process_report)

Collateralization

• 100% onchain USDC backing — all deposits are USDC, deployed into Sky-governed lending venues (sUSDS Lender ~97% and Spark USDC Lender ~3%)
• Collateral quality: sUSDS is backed by over-collateralized loans and RWA (Treasury bills) via MakerDAO. Spark USDC Lender supplies into Spark Lend's USDC market (Sky sub-DAO infrastructure)
• No leverage — unlike yvUSD's looper strategies, these are simple deposits into savings rate and lending products
• All positions are fully redeemable — sUSDS and Spark vaults support standard ERC-4626 / aToken withdrawal. USDS converts 1:1 to DAI via the Exchanger

Provability

• yvUSDC-1 exchange rate: Calculated onchain via ERC-4626 standard (convertToAssets()/convertToShares()). Fully programmatic, no admin input
• Strategy positions: Each strategy's totalAssets() reads the underlying vault share balance (yvUSDS or sUSDS) and converts to USDC equivalent onchain
• sUSDS rate: The Sky Savings Rate is set by Sky Governance and applied onchain via the pot/ssr mechanism. The sUSDS exchange rate increases continuously based on the SSR
• Profit/loss reporting: Profits are reported by keepers via process_report() and locked for gradual distribution over 10 days (profitMaxUnlockTime). Losses are immediately reflected in PPS

Liquidity Risk

• Primary exit: Redeem yvUSDC-1 for USDC via ERC-4626 withdraw()/redeem(). Triggers reverse pipeline through sUSDS → USDS → DAI → USDC (~97% of debt) or direct Spark Lend withdrawal (~3%)
• Highly liquid underlying: sUSDS holds multi-billion-dollar USDS reserves; Spark Lend's USDC market also has deep lending liquidity. The vault's ~$29.84M is a small fraction of underlying pool capacity
• PSM liquidity: The MakerDAO PSM Lite provides deep DAI ↔ USDC liquidity at 0% fee. PSM capacity is managed by Sky Governance and typically holds billions of USDC
• No DEX liquidity needed in the base case — exit is via the protocol's own pipeline (PSM + Exchanger), not DEX AMMs. Uniswap V3 fallback applies only if PSM fees rise above 0.05%
• Same-value asset: USDC-denominated vault token — no price divergence risk from the underlying
• No withdrawal queue or cooldown — atomic redemption through the pipeline
• Deposit limit: $50M cap — generous relative to current TVL of $29.84M

Centralization & Control Risks

Governance

The yvUSDC-1 vault uses the standard Yearn V3 governance pattern via the Yearn V3 Role Manager contract.

Governance hierarchy:

Position	Address	Threshold	Roles on Vault
Daddy (ySafe)	0xFEB4acf3df3cDEA7399794D0869ef76A6EfAff52	6-of-9	All 14 roles (full admin)
Brain	0x16388463d60FFE0661Cf7F1f31a7D658aC790ff7	3-of-8	QUEUE, REPORTING, DEBT, DEPOSIT_LIMIT, EMERGENCY
Security	0xe5e2Baf96198c56380dDD5E992D7d1ADa0e989c0	4-of-7	Manages via Role Manager
Strategy Manager (Timelock)	0x88Ba032be87d5EF1fbE87336b7090767F367BF73	7-day delay	Strategy additions via Role Manager
Keeper	0x604e586F17cE106B64185A7a0d2c1Da5bAce711E	Bot	REPORTING only
Debt Allocator	0x1e9eB053228B1156831759401dE0E115356b8671	Bot	REPORTING + DEBT_MANAGER

ySafe 6-of-9 multisig signers include publicly known contributors: Mariano Conti (ex-MakerDAO), Leo Cheng (C.R.E.A.M.), 0xngmi (DeFiLlama), Michael Egorov (Curve), and others (source).

Governance assessment:

1. No EOA role concentration — all sensitive roles are held by multisigs
2. Strategy additions go through a 7-day timelock via the TimelockController (delay increased from initial 24h to 7 days on Feb 22, 2025)
3. Standard Yearn governance — same setup used across 37 vaults, battle-tested pattern
4. Immutable vault — no proxy upgrades possible

Programmability

• Exchange rate (PPS): Calculated onchain algorithmically via ERC-4626. Fully programmatic, no admin input
• Vault operations: Deposit/withdraw are permissionless onchain transactions
• Strategy profit/loss: Reported programmatically by keepers via process_report(). Profits unlock linearly over 10 days
• Debt allocation: Managed by both the Debt Allocator (automated) and Brain multisig (manual). Currently split across four strategies
• V3 vaults are immutable — no proxy upgrades, no admin-changeable implementation

External Dependencies

Dependency	Criticality	Notes
Sky / sUSDS	Critical	~97% of current allocation via the sUSDS Lender. Multi-billion-dollar sUSDS TVL. Blue-chip, extensively audited, $10M bug bounty
Spark Lend (Sky sub-DAO)	High	~3% of current allocation via Spark USDC Lender. Spark is a Sky sub-DAO; admin keys live under Sky governance
MakerDAO PSM Lite	High	USDC ↔ DAI conversion at 1:1 for the sUSDS Lender path. 0% fee. Deep liquidity. Audited by ChainSecurity and Cantina
Sky DAI-USDS Exchanger	High	DAI ↔ USDS 1:1 conversion for the sUSDS Lender path. Core Sky infrastructure
Uniswap V3 (fallback)	Low	Only used if PSM fee exceeds 0.05%. Currently not active (PSM fee is 0%)

Dependency quality: All funded dependencies sit under Sky / Sky sub-DAO governance — effective Sky-governance exposure is ~100% of debt at this snapshot. Sky itself is top-tier (8+ years of history, $10M bug bounty, multi-billion-dollar sUSDS TVL), but the single-ecosystem concentration is materially worse than the prior 41% Sky / 59% Morpho split. The Morpho Yearn USDC Compounder that was queued at the May 5 snapshot has been revoked, eliminating that on-chain re-diversification optionality until a new Morpho strategy is reproposed via the 7-day timelock. This concentration is reflected in the dependency subscore.

Operational Risk

• Team: Yearn Finance — established since 2020, publicly known contributors. The ySafe 6-of-9 multisig has 9 named signers including prominent DeFi figures
• Governance: Standard Yearn V3 Role Manager — the same governance used across 37 vaults, with clear role separation (Daddy, Brain, Security, Keeper, Debt Allocator)
• Documentation: Comprehensive Yearn V3 documentation. Strategy code is verified on Etherscan
• Legal: Yearn Finance has converted its ychad.eth multisig into a BORG (cybernetic organization) via YIP-87, wrapping it in a Cayman Islands foundation company with smart contract governance restrictions
• Incident response: Yearn has demonstrated incident response capability across 4 historical events (all V1/legacy). V3 framework has not been tested under stress. The $200K Immunefi bug bounty provides a responsible disclosure channel
• V3 immutability: Vault contracts cannot be upgraded — this eliminates proxy upgrade risk

Monitoring

Existing Monitoring Infrastructure

Yearn maintains an active monitoring system via the monitoring-scripts-py repository. yvUSDC-1 is actively monitored:

• Large flow alerts (yearn/alert_large_flows.py): Runs hourly via GitHub Actions. yvUSDC-1 is in the monitored vault list. Alerts on deposits/withdrawals exceeding threshold via Telegram
• Endorsed vault check (yearn/check_endorsed.py): Runs weekly, verifies all Yearn V3 vaults are endorsed onchain via the registry contract
• Timelock monitoring (timelock/timelock_alerts.py): Monitors the Yearn TimelockController (Strategy Manager) across 6 chains

Key Contracts

Contract	Address	Monitor
yvUSDC-1 Vault	0xBe53A109B494E5c9f97b9Cd39Fe969BE68BF6204	PPS (convertToAssets(1e6)), totalAssets(), totalDebt(), totalIdle(), Deposit/Withdraw events
USDC to sUSDS Lender	0x7130570BCEfCedBe9d15B5b11A33006156460f8f	totalAssets(), current_debt, isShutdown(), keeper report frequency
Spark USDC Lender	0x25f893276544d86a82b1ce407182836F45cb6673	totalAssets(), current_debt, isShutdown(), keeper report frequency
ySafe (Daddy)	0xFEB4acf3df3cDEA7399794D0869ef76A6EfAff52	Signer/threshold changes, submitted transactions
Accountant	0x5A74Cb32D36f2f517DB6f7b0A0591e09b22cDE69	Fee changes, config updates
Sky Savings Rate	0xa3931d71877C0E7a3148CB7Eb4463524FEc27fbD	SSR rate changes, sUSDS TVL

Critical Events to Monitor

• PPS decrease — any decrease in convertToAssets(1e6) indicates a loss event. Should only increase
• Strategy additions/removals — StrategyChanged events indicate portfolio changes (new strategies go through 7-day timelock)
• Debt allocation changes — UpdatedMaxDebtForStrategy and DebtUpdated events
• Emergency actions — Shutdown event on vault
• ySafe signer/threshold changes — governance integrity
• SSR rate changes — Sky Governance may adjust the savings rate, affecting yield
• PSM fee changes — if tin or tout are set above 0, it may trigger the Uniswap V3 fallback path

Monitoring Functions

Function	Contract	Purpose	Frequency
convertToAssets(1e6)	Vault	PPS tracking	Every 6 hours
totalAssets()	Vault	Total TVL	Daily
totalDebt() / totalIdle()	Vault	Capital deployment ratio	Daily
strategies(address)	Vault	Per-strategy debt, last report time	Daily
get_default_queue()	Vault	Withdrawal queue composition	Weekly
getThreshold() / getOwners()	ySafe	Governance integrity	Weekly
getMinDelay()	ySafe	Delay change detection	Weekly
ssr()	Sky Pot	Savings rate	Weekly

Reassessment Triggers

• Time-based: Reassess in 6 months (November 2026) or annually
• TVL-based: Reassess if TVL exceeds $100M or changes by more than ±50%
• Incident-based: Reassess after any exploit, strategy loss, governance change, or Sky / Spark Lend / Morpho incident
• Allocation-based: Reassess if a new non-Sky strategy is added to the queue (would re-introduce a non-Sky leg and potentially step the Cat 2C dependency score back down to 2.0 / final to 1.2). Conversely, reassess if any new Sky-coupled strategy increases concentration further
• SSR-based: Reassess if Sky Savings Rate drops below 2% (may indicate Sky governance issues) or if PSM fees are introduced
• Governance-based: Reassess if ySafe composition changes (signer additions/removals, threshold changes)

---

Appendix: Contract Architecture

┌─────────────────────────────────────────────────────────────────────┐
│                         VAULT LAYER                                  │
│                                                                      │
│  ┌───────────────────────┐                                          │
│  │  yvUSDC-1 (v3.0.2)   │                                          │
│  │  ERC-4626, immutable  │                                          │
│  │  0xBe53...6204        │                                          │
│  │                       │                                          │
│  │  deposit() / redeem() │                                          │
│  │  totalAssets()        │                                          │
│  └──────────┬────────────┘                                          │
│             │ deploys USDC to 3 queued strategies (2 funded)         │
│             │                                                        │
│  ┌──────────▼──────────────────────────────────────────────────────┐│
│  │  STRATEGIES (by allocation, May 11 snapshot)                     ││
│  │                                                                  ││
│  │  ┌─────────────────────────────────────────────────────────┐    ││
│  │  │ SKY (~97%)                                              │    ││
│  │  │  USDC to sUSDS Lender                       97.15%      │    ││
│  │  │  Pipeline: USDC → DAI (PSM 1:1) → USDS → sUSDS         │    ││
│  │  └─────────────────────────────────────────────────────────┘    ││
│  │  ┌─────────────────────────────────────────────────────────┐    ││
│  │  │ SPARK (Sky sub-DAO) (~3%)                               │    ││
│  │  │  Spark USDC Lender                          2.85%       │    ││
│  │  │  Pipeline: USDC → Spark Lend (direct)                   │    ││
│  │  └─────────────────────────────────────────────────────────┘    ││
│  │                                                                  ││
│  │  Queued (0 debt):                                                ││
│  │  - USDC to USDS Depositor                                        ││
│  │                                                                  ││
│  │  Revoked between May 5 and May 11:                               ││
│  │  - Morpho Yearn USDC Compounder (added 2026-04-30)               ││
│  └─────────────────────────────────────────────────────────────────┘│
└──────────────────────────────────────────────────────────────────────┘
                                │
                  deposits into underlying protocols
                                │
┌───────────────────────────────▼──────────────────────────────────────┐
│                    UNDERLYING PROTOCOLS                                │
│                                                                       │
│  ┌──────────────────────────┐    ┌──────────────────────────┐        │
│  │  Sky / sUSDS             │    │  Spark Lend (Sky sub-DAO)│        │
│  │  Multi-billion TVL       │    │  USDC market             │        │
│  │  SSR: ~4.0% APY          │    │  Sky-governed            │        │
│  │  8+ years, $10M bounty   │    │  Audited (ChainSec, etc.)│        │
│  │  ~97% of vault           │    │  ~3% of vault            │        │
│  └──────────────────────────┘    └──────────────────────────┘        │
│  ┌──────────────────────────┐    ┌──────────────────────────┐        │
│  │  MakerDAO PSM Lite       │    │  Sky DAI-USDS Exchanger  │        │
│  │  USDC ↔ DAI at 1:1      │    │  DAI ↔ USDS at 1:1      │        │
│  │  0% fee (tin=tout=0)     │    │  No fee                  │        │
│  └──────────────────────────┘    └──────────────────────────┘        │
└───────────────────────────────────────────────────────────────────────┘

Data flow: User deposits USDC → yvUSDC-1 vault → sUSDS Lender (~97%)
converts USDC → DAI (PSM) → USDS (Exchanger) → sUSDS; Spark Lender (~3%)
supplies USDC directly to Spark Lend. Profits reported by Keeper, locked
for 10 days. Withdrawals reverse the pipeline (atomic, no cooldown).

Appendix: TimelockController Role Structure

TimelockController 0x88Ba032be87d5EF1fbE87336b7090767F367BF73 — deployed at block 24,242,692 with admin = address(0). Same timelock used by yvUSD and 37+ other Yearn V3 vaults.

Timelock Roles

Role	Holder	Type	Notes
DEFAULT_ADMIN	No holder	—	Never granted (admin = address(0) at construction). No one can grant/revoke roles outside the propose→wait→execute flow
TIMELOCK_ADMIN	Timelock itself (0x88Ba032be87d5EF1fbE87336b7090767F367BF73)	Contract	Only the timelock can admin its own roles. Config changes (delay, role grants) must go through the 7-day delay
PROPOSER	Daddy/ySafe (0xFEB4acf3df3cDEA7399794D0869ef76A6EfAff52)	6-of-9 Safe	Only proposer — no one else can initiate timelocked operations
EXECUTOR	Daddy/ySafe (0xFEB4acf3df3cDEA7399794D0869ef76A6EfAff52)	6-of-9 Safe	Can execute queued proposals directly
EXECUTOR	TimelockExecutor (0xf8f60bf9456a6e0141149db2dd6f02c60da5779b)	Contract	Wrapper contract — delegates execution to its internal executor list (see below)
CANCELLER	Daddy/ySafe (0xFEB4acf3df3cDEA7399794D0869ef76A6EfAff52)	6-of-9 Safe	Can cancel pending proposals
CANCELLER	Brain (0x16388463d60FFE0661Cf7F1f31a7D658aC790ff7)	3-of-8 Safe	Can cancel pending proposals

TimelockExecutor Contract

0xf8f60bf9456a6e0141149db2dd6f02c60da5779b — governance-gated wrapper around the TimelockController. Only addresses on its internal executor list can call execute() through it.

Parameter	Value
Governance	Brain (0x16388463d60FFE0661Cf7F1f31a7D658aC790ff7) — only Brain can add/remove internal executors
Internal executor 1	Brain (0x16388463d60FFE0661Cf7F1f31a7D658aC790ff7)
Internal executor 2	Deployer EOA (0x1b5f15DCb82d25f91c65b53CEe151E8b9fBdD271)

Execution Paths for Queued Proposals

All paths require Daddy (6/9) to first propose the operation and a 7-day wait:

1. Daddy (6/9) executes directly (holds EXECUTOR_ROLE on timelock)
2. Brain (3/8) executes via TimelockExecutor contract
3. Deployer EOA executes via TimelockExecutor contract

Why the Delay Cannot Be Bypassed

To change the timelock delay (e.g., reduce from 7 days), an attacker would need to:

1. Control Daddy (6/9) to propose updateDelay() — the only PROPOSER
2. Wait 7 days — Brain or Daddy can cancel during this window
3. Execute via Daddy, Brain, or the EOA — but the operation is already visible onchain for 7 days

DEFAULT_ADMIN was never granted, so no one can grant themselves PROPOSER or TIMELOCK_ADMIN to skip this flow. The timelock holds TIMELOCK_ADMIN but can only act on it through its own propose→wait→execute cycle.