How Does mStable Work?

Yield|Risk C|5 mechanisms|5 interactions

mStable's mPT-sUSDe vault offers ~15% APY by combining Ethena's sUSDe yield with Pendle fixed-rate tokens and Aave leveraged looping (up to 7.5x). This is a sophisticated yield strategy that stacks three DeFi protocols together. While the returns are attractive, the leverage means losses are amplified — a modest stablecoin depeg could trigger cascading liquidations. The original mStable protocol was rebuilt in late 2025 with this new vault architecture.

TVL

$3M

Sector

Yield

Risk Grade

C

Value Grade

C+

Core Mechanisms

Yield > Fixed Rate > Principal Token

Pendle PT fixed yield on sUSDe — locks in fixed return by purchasing discounted principal tokens at maturity

Standard Pendle PT mechanism; yield depends on sUSDe underlying rate and time to maturity

Leverage > Recursive Lending > Loop

Novel

Aave recursive lending loop — borrows against PT-sUSDe collateral and re-deposits up to ~7.5x leverage

Amplification of fixed-rate yield through recursive borrowing is a newer pattern with compounded liquidation risk

Yield > Basis Trade > Delta-Neutral

Inherited Ethena sUSDe basis trade — short perp funding rate capture on centralized exchanges

sUSDe yield comes from Ethena's CEX basis trade; vault inherits all Ethena counterparty risks

Vault > Automated Rebalancing

Novel

mStable vault auto-rebalances between PT maturities and manages Aave health factor

Automated management of leveraged positions across multiple protocols adds operational complexity

Collateral > Yield-Bearing > Staked Stablecoin

sUSDe as base collateral — staked USDe earning Ethena protocol yield

Standard yield-bearing stablecoin used as collateral throughout the vault strategy

How the Pieces Interact

Aave Recursive Lending LoopsUSDe Basis TradeCritical

7.5x leverage on sUSDe means a modest sUSDe depeg (>5%) triggers cascading Aave liquidations, with losses amplified by the full leverage ratio

Pendle PT Fixed YieldAave Recursive Lending LoopHigh

PT maturity mismatch with Aave borrow positions: if PT value drops before maturity due to rate changes, health factor deteriorates across all looped positions simultaneously

Automated RebalancingAave Recursive Lending LoopHigh

Automated rebalancing during high volatility may fail to unwind leveraged positions fast enough, especially during Aave oracle lag or gas spikes

Pendle PT Fixed YieldsUSDe Basis TradeMedium

If Ethena yield drops sharply, PT discount widens, creating unrealized losses on existing PT positions that affect the entire vault NAV

sUSDe CollateralAutomated RebalancingMedium

sUSDe redemption delays during market stress may prevent timely rebalancing, leaving the vault exposed to deteriorating positions

What Could Go Wrong

  1. Leveraged Aave looping (up to 7.5x) amplifies losses if sUSDe depegs or Pendle PT matures unfavorably
  2. Multi-layer smart contract risk spanning Ethena, Pendle, and Aave — any single exploit cascades through the vault
  3. Ethena counterparty exposure: sUSDe depends on centralized exchange basis trades that can unwind during market stress
  4. Pendle PT maturity mismatch risk: locked fixed-rate positions may suffer losses if redeemed early or rolled at worse rates

sUSDe Depeg Cascade Through Leveraged Loop

Moderate

Trigger: sUSDe depegs >5% due to Ethena basis trade unwind or CEX counterparty failure

  1. 1.sUSDe drops below peg as Ethena basis trades unwind during market stress PT-sUSDe value drops proportionally, Aave health factor deteriorates across all loop iterations
  2. 2.Aave liquidation triggers on outermost loop position Forced selling of PT-sUSDe further depresses price, triggering liquidations on inner loop positions
  3. 3.Cascading liquidations across all 7+ loop iterations Vault NAV drops 30-60% as leveraged positions are unwound at distressed prices
  4. 4.Automated rebalancer cannot keep up with liquidation cascade Remaining vault assets are significantly impaired; depositors face major losses

Risk Profile at a Glance

Mechanism Novelty10/15
Interaction Severity12/20
Oracle Surface5/10
Documentation Gaps4/10
Track Record5/15
Scale Exposure0/10
Regulatory Risk3/10
Vitality Risk6/10
C

Overall: C (45/100)

Lower score = safer

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