> ## Documentation Index > Fetch the complete documentation index at: https://docs.l2pass.com/llms.txt > Use this file to discover all available pages before exploring further. # Overview > Earn sustainable yield on Ethereum. No lockups. Instant withdrawals. L2Pass sUSDD Recursive Yield Strategy **The sUSDD Recursive Yield Strategy** is an institutional-grade USDT Vault on Ethereum, engineered to capture capital-efficient, leveraged exposure to sUSDD. By utilizing the Morpho Blue lending protocol and the USDD Peg Stability Module (PSM), the strategy maximizes yield while maintaining a disciplined risk profile. ## Strategy Summary **L2Pass sUSDD Recursive Yield** is a non-custodial, institutional-grade strategy that maximizes yield by capturing the spread between **sUSDD** staking rewards and **USDT** borrowing costs. Using an automated "Engine" built on the **ERC-4626** standard, the vault executes a recursive leverage loop, converting deposited USDT into sUSDD, supplying it as collateral on **Morpho Blue**, and using flashloans to multiply the position. This process amplifies native staking returns while all harvested rewards are auto-compounded back into the collateral base to increase the value of vault shares. To protect user principal, the strategy features robust, real-time risk mitigation including automated deleveraging triggers and peg monitoring. The system continuously tracks the **1:1 conversion efficiency** of the USDD/USDT Peg Stability Module (PSM) and the net interest spread; if borrow rates spike or liquidity drops, the vault automatically unwinds positions to maintain a safe Loan-to-Value (LTV) buffer. This modular architecture ensures the strategy remains capital-efficient and defensive during market volatility, providing a transparent, rules-based alternative to traditional stablecoin farming. *** ## Core Architecture Layers The L2Pass architecture is an institutional-grade, segregated framework designed for modularity and high-fidelity risk management. It utilizes a "Hub-and-Engine" topology that strictly decouples capital accounting from execution logic. #### **A. Accounting Layer (Hub)** The Hub serves as the primary liquidity gateway and the single source of truth for the fund’s net asset value. * **ERC-4626 Standard:** A fully compliant tokenized vault interface that manages the minting and burning of vault shares. Provides real-time NAV calculation by aggregating total assets deployed within the active Strategy Engine. * **Total Capital Efficiency:** Unlike traditional models, the Hub maintains **zero idle reserves**. 100% of deposited USDT is immediately deployed to the execution layer to maximize yield generation from the first block. #### **B. The Execution Layer (Strategy Engine)** A dedicated logic module that executes the fund’s yield mandates without direct access to the Hub's core accounting records. * **Recursive Spread Execution:** Orchestrates the automated sUSDD/USDT spread strategy. It manages the conversion of USDT into sUSDD and the subsequent leverage loops on **Morpho Blue**. * **Atomic Leverage Logic:** Utilizes flashloans to achieve target exposure in a single transaction, ensuring the vault reaches its optimal yield profile instantaneously upon capital deployment. #### **C. The Sentinel Layer** A dedicated monitoring suite that acts as the fund's autonomous circuit breaker. * **Peg & Rate Monitoring:** Continuously tracks the 1:1 conversion efficiency of the USDD/USDT Peg Stability Module (PSM) and the sUSDD/USDT interest rate differential. * **Automated Intervention:** Keeper-driven logic triggers immediate deleveraging or a full "Safe Exit" if volatility, PSM liquidity, or borrow rates breach predefined safety thresholds. *** ## Key Properties * **Real-time Algorithmic Surveillance:** 24/7 automated monitoring of PSM liquidity, Morpho borrow rates, the USDD oracle price feed, and administrative governance activity to ensure constant protocol health. * **Automated Unwind Controls:** Hard-coded safeguard parameters that trigger a defensive deleveraging or a total migration back to USDT if risk parameters—such as PSM depth or LTV—are compromised. * **Zero-Slippage Execution:** By routing all primary conversions through the PSM, the vault bypasses traditional AMM fees and slippage, ensuring 100% capital efficiency for participants. * **Native USDT Accrual:** Yield is captured directly in the Vault Share price in native USDT. The strategy avoids the volatility of "points" or inflationary reward tokens, focusing on hard-asset growth. * **On-Demand Liquidity:** The vault operates with no lock-ups or cooldown periods. The architecture remains fully accessible for instantaneous entry and exit, reflecting a truly liquid on-chain strategy. ## Yield & Incentives Returns within the sUSDD Recursive Yield Strategy are generated through a multi-layered approach that prioritizes capital efficiency and protocol-native rewards. * **Recursive Spread Capture** The primary yield engine capitalizes on the positive spread between [sUSDD staking rewards](https://app.usdd.io/eth/earn) and the [Morpho Blue USDT borrow rate](https://app.morpho.org/). This spread is amplified through an automated recursive looping mechanism, maximizing the productivity of deposited capital without manual intervention. * **Programmatic Incentives** Performance is further enhanced by external rewards (currently distributed via [Merkl](https://merkl.xyz/)). These incentives are dynamically integrated into the strategy to either bolster the underlying sUSDD yield or subsidize the market borrow costs, providing an additional layer of optimization for vault participants. *** ## Fee Structure | Fee Category | Rate | Note | | :------------------ | :--- | :-------------------------------------- | | **Deposit Fee** | 0% | No cost to enter the vault | | **Withdrawal Fee** | 0% | No cost to exit the vault | | **Management Fee** | 0% | No managment fee | | **Performance Fee** | 15% | Applied only to realized yield/rewards. | ## Resources | Resource | Link | | :---------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------------- | | **L2Pass sUSDD Recursive Vault UI** | [vault.l2pass.com](https://vault.l2pass.com) | | **USDD** | [usdd.io](https://usdd.io/) | | **PSM (Ethereum)** | [app.usdd.io/eth/psm](https://app.usdd.io/eth/psm) | | **USDD Metrics** | [DefiLlama - USDD](https://defillama.com/stablecoin/usdd) | | **sUSDD/USDT Market** | [Morpho Blue Market](https://app.morpho.org/ethereum/market/0x29ae8cad946d861464d5e829877245a863a18157c0cde2c3524434dafa34e476/susdd-usdt) | | **L2Pass Website** | [l2pass.com](https://l2pass.com) | | **Audit Vault** | [Github](https://github.com/L2PASS/audit/blob/main/wake-arena-usdd-morpho-vault.pdf) | | **Audit PSM** | [docs.usdd.io](https://docs.usdd.io/security/audits) | | **Audit USDD** | [docs.usdd.io](https://docs.usdd.io/security/audits) | *** Answers to common questions regarding strategy mechanics. Key risk disclosures, assumptions, and protocol limitations. *** Join the L2Pass Telegram group for real-time updates and direct community support.