# \[RFC\] Onboard \`sUSDS/sUSDC\` ark to Arbitrum USDC Fleet

**URL:** <https://forum.summer.fi/t/rfc-onboard-susds-susdc-ark-to-arbitrum-usdc-fleet/179>\
**Category:** Request for Comment \[RFCs\]\
**Tags:** usdc, arbitrum, rfc, susds\
**Created:** [April 22, 2025, 2:07pm UTC](https://forum.summer.fi/t/rfc-onboard-susds-susdc-ark-to-arbitrum-usdc-fleet/179 "2025-04-22T14:07:29Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![halaprix](https://yyz1.discourse-cdn.com/flex009/user_avatar/forum.summer.fi/halaprix/32/13_2.png) [@halaprix](https://forum.summer.fi/u/halaprix)\
**Post date:** [April 22, 2025, 2:07pm UTC](https://forum.summer.fi/t/rfc-onboard-susds-susdc-ark-to-arbitrum-usdc-fleet/179/1 "2025-04-22T14:07:29Z")

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**Summary** This proposal suggests adding an sUSDS Ark to the recently onboarded Arbitrum USDC Vault. This Ark will utilize the Sky Savings Rate (SSR) module, currently offering a yield of approximately 4.5%, as a new yield source for the vault.

**Motivation** To further diversify the yield strategies available to the Arbitrum USDC Vault and capitalize on the attractive yield offered by the Sky Protocol’s Sky Savings Rate (SSR) via its sUSDS token. This enhances the overall return potential for vault depositors.

**Specification**

- **New Ark:** Sky Savings Rate (SSR) Ark utilizing sUSDS through `sUSDC`.
- **Target Vault:** Arbitrum USDC Vault.
- **Network:** Arbitrum.
- **Yield Mechanism:** The Ark will deposit the vault’s USDC into the Sky Savings Rate module (SSR). This process was simplified thanks to Spark `sUSDC` (`0x940098b108fB7D0a7E374f6eDED7760787464609`) , which accrues yield at the prevailing Sky Savings Rate (currently ~4.5%). [sUSDC Token – Spark Docs](https://docs.spark.fi/dev/savings/susdc-token)
- **Implementation:** `ERC4626Ark` implementation can be used out of the box.

**Risk Level:** Lower Risk. Primary risks involve smart contract security of the Sky Protocol (sUSDS/SSR contracts) and potential fluctuations in the Sky Savings Rate.

**Voting** Seek initial feedback. If positive, proceed to an on-chain vote to approve the addition of the sUSDS Ark, potentially launching with a 0 deposit cap initially for safety.

`sUSDC` would nicely supplement current arbitrum USDC options for the fleet.

 ![image](https://canada1.discourse-cdn.com/flex009/uploads/summer/original/1X/74a7686b50ee1c00b4c74cff733eb5e74380893d.png)  
 ![image](https://canada1.discourse-cdn.com/flex009/uploads/summer/original/1X/f5592f55bdfce22ebe4da4431d0d87afdbb325a4.jpeg)

[@Recognized\_Delegates](https://forum.summer.fi/groups/recognized_delegates) @BlockAnalitica

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**Author:** ![Raphael\_Anode](https://yyz1.discourse-cdn.com/flex009/user_avatar/forum.summer.fi/raphael_anode/32/476_2.png) [@Raphael\_Anode](https://forum.summer.fi/u/Raphael_Anode)\
**Post date:** [April 22, 2025, 3:19pm UTC](https://forum.summer.fi/t/rfc-onboard-susds-susdc-ark-to-arbitrum-usdc-fleet/179/2 "2025-04-22T15:19:45Z")

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sUSDS is the “risk free rate” in DeFi, arguably. Recent move to Arbitrum makes this possible natively. Supported.

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**Author:** ![FBrinkkemper](https://yyz1.discourse-cdn.com/flex009/user_avatar/forum.summer.fi/fbrinkkemper/32/7_2.png) [@FBrinkkemper](https://forum.summer.fi/u/FBrinkkemper)\
**Post date:** [April 22, 2025, 5:26pm UTC](https://forum.summer.fi/t/rfc-onboard-susds-susdc-ark-to-arbitrum-usdc-fleet/179/3 "2025-04-22T17:26:22Z")

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I would argue that the ‘lower risk’ summer vaults should be regarded as the ‘risk free rate’ in the long term.

We support the addition of sUSDS/sUSDC to the arb fleet.

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**Author:** ![jensei](https://yyz1.discourse-cdn.com/flex009/user_avatar/forum.summer.fi/jensei/32/69_2.png) [@jensei](https://forum.summer.fi/u/jensei)\
**Post date:** [April 23, 2025, 8:10am UTC](https://forum.summer.fi/t/rfc-onboard-susds-susdc-ark-to-arbitrum-usdc-fleet/179/4 "2025-04-23T08:10:09Z")

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Looks like a solid addition to the Arbitrum USDC Vault — sUSDC via SSR offers a stable yield and fits well within the existing architecture. Makes sense!

— jensei