Summary
This SIP proposes integrating the Sky Savings Rate (SSR) via sUSDS as a new Ark into the USDC Arbitrum (Lower Risk) vault in the Summer Protocol. Adding the sUSDS Ark diversifies yield sources for the Arbitrum USDC vault by tapping into the yield generated by the Sky Protocol’s SSR module, currently offering approximately 4.5%.
Motivation
Expand Yield Sources: Gains exposure to the Sky Savings Rate yield, complementing existing DeFi lending ARKs within the Arbitrum USDC vault.
Attractive Yield: Leverages the current ~4.5% yield offered by the Sky Savings Rate via sUSDS.
Increase Vault Utility: Enhances the options and potential returns for depositors in the Arbitrum USDC Vault.
Diversification: Adds a different type of yield-bearing stablecoin strategy (ERC-4626 wrapper for yield) to the vault’s portfolio.
Specifications
Parameter
Value
Vault
USDC Arbitrum — Lower Risk
Network
Arbitrum
New ARK
sUSDS (Sky Savings Rate)
Contract (sUSDC)
0x940098b108fB7D0a7E374f6eDED7760787464609
Risk Level
Lower Risk (pending final review)
Next Steps
Finalize Ark Deplyment:
Submit SIP to Tally: Proceed with the Summer DAO on-chain vote for deployment and activation of the sUSDS Ark.
Risk Assessment: Request @BlockAnalitica (or relevant risk team) to complete a final risk assessment and recommend parameters.
BA-Labs supports the proposed addition of Sky’s sUSDS as an ARK on Arbitrum on Lazy Summer Protocol, with the goal of broadening yield sources.
In the effort for multichain deployments, Sky protocol has recently expanded sUSDS offering to Arbitrum, after initially introducing it to Base and GnosisChain (in addition to Mainnet). Users can deposit either USDC or USDS to earn predictable APY in the deposit token, set by SKY governance.
Note that sUSDS collateral is already onboarded both directly and via numerous ARKs on SummerFi Lazy protocol deployments on Mainnet and Base. The liquidity on latest Arbitrum deployment currently stands at ~$22m, which will be taken into account in the proposed parameters for this ARK we’ll post below as a separate post when this proposal gets pushed to a vote.
Appreciate the clear and contextual endorsement from the @BlockAnalitica team.
Sky’s multichain expansion and the consistent framing of sUSDS across Mainnet, Base, and now Arbitrum adds confidence in the integration’s operational maturity.
From a vault design perspective, I’d be curious to see how sUSDS’s predictable rate interacts with other ARKs over time—particularly in volatile DeFi rate regimes. That sort of stability could become an anchor leg in risk-balanced allocations across chains.
We’ve integrated and run our risk model to assess the sUSDS Ark on Arbitrum under the low-risk Fleet Arbitrum USDC and reviewed the results. The following initial parameters are being proposed:
Ark
Symbol/Vault
maxCap
Max. %TVL
maxInflow
maxOutflow
sky
sUSDS
36,000,000
92.00%
2,400,000
11,000,000
The cooldown period for all Arks in this Fleet is 10 minutes.
These parameters ensure the fleet operates within controlled risk limits while accommodating expected demand.
