Marat Nusurov

Elastic Modules

Company: HodlTree
Role: Senior Solidity Developer
Stack: Solidity 0.8.0 · Truffle · Balancer V2 · OpenZeppelin Contracts · Web3.js
Period: 09/2020 - 05/2021

Overview

Sophisticated Ethereum DeFi protocol implementing elastic and volatile liquidity pools with automated loss/profit compensation mechanisms. The system integrates with Balancer Protocol to enable dynamic yield strategies with configurable risk parameters and deterministic contract deployment. Two primary trading pairs deployed: sUSD/sETH (75/25 ratio) and USDC/BAL (50/50 ratio), each with independent liquidity management and collateral tracking.

Technical Scope

Elastic Pool (EPT Token)

• ERC20 token representing pool shares with automatic loss/profit compensation
• Configurable compensation limit (default 50%) protecting against unrealized losses
• Excess profits split between platform fees and worker incentives
• Time-based withdrawal holds for capital stability
• Real-time balance reconciliation with Balancer pools

Volatile Pool (VPT Token)

• ERC20 token minted based on deposit coefficient independent of time
• Tiered yield strategy capturing volatility premiums
• Seamless composition with Elastic Pool for multi-strategy access
• Dynamic rebalancing through multi-pool swap chains

Balancer Protocol Integration

• Joins and exits Balancer pools (USDC-WETH for sUSD/sETH; BAL routing for USDC/BAL)
• BAL token reward distribution with automated swaps via intermediate routing
• Dynamic rebalancing through multi-pool swap chains
• Real-time pool data updates for fair pricing

Deterministic Contract Deployment via Factory

• All four contracts have circular constructor-argument dependencies - each requires the addresses of contracts not yet deployed
• Factory acts as sole deployer, pre-computing all addresses via CREATE deterministic formula (keccak256(rlp([deployer, nonce]))) before any contract exists
• All four contracts deployed atomically in a single transaction with cross-references already resolved
• Each deployed address verified post-construction against expected value

Risk Management & Safety

• Reentrancy guards on all state-changing functions
• Safe token transfers with explicit error handling
• Emergency stop mechanism with cascading control
• Owner-based access control with multi-signature capability

Key Engineering Decisions

Decision	Rationale
Balancer V2 over Uniswap	Multi-asset pool support enables more flexible collateral ratios (75/25, 50/50) without AMM constant product constraints
Deterministic deployment via CREATE (Factory)	Sequential deployment is structurally impossible due to circular constructor-argument dependencies; Factory pre-computes all addresses before any contract is live
Three-tier fee architecture	Aligns incentives between platform, workers, and users; loss compensation funded from performance profits
Time-based withdrawal holds	Prevents flash loan attacks and encourages long-term capital commitment
Period-based accounting (VPStorage)	Enables fair distribution of BAL rewards and platform fees across different entry times without per-user iteration

Links & Archives

• GitHub: Not public (company policy)
• Contracts Deployed:
  • sUSD/sETH 75/25 v1.0: ElasticPool · VolatilePool · ReservePool · VPStorage
  • USDC/BAL 50/50 v1.0: ElasticPool · VolatilePool · ReservePool · VPStorage
• Articles: Medium - HodlTree: Elastic Modules Explained - Local Copy

Technical Insights

• EPT is a loss-compensation voucher, not an LP token. Elastic Pool positions are tracked internally per-user - no ERC20 tokens are minted on deposit. EPT tokens are minted only on withdrawal at a loss, functioning as a typed claim against the reserve. Users redeem them at ReservePool 1:1 for the underlying by burning. This cleanly separates LP accounting from the insurance claim layer.

• Volatile Pool depositors are the protocol’s implicit risk underwriters. Their USDC flows directly to ReservePool, funding EPT redemptions. The 1.5× VPT mint coefficient makes the asymmetry explicit: Volatile Pool depositors receive amplified exposure to BAL rewards in exchange for bearing the counterparty risk of ElasticPool’s downside protection.

See HodlTree page for additional context.