What is restaking and how EigenLayer turns staked ETH into shared security

Restaking lets staked ETH secure additional protocols beyond Ethereum, creating a marketplace for decentralized trust but introducing new layers of slashing risk. Summary Restaking allows already-staked ETH to simultaneously secure other protocols (called actively validated services, or AVSs), extending Ethereum’s economic security without requiring new capital. EigenLayer, launched on Ethereum mainnet in June 2023, is the largest restaking protocol, with over $15 billion in total value restaked at its peak. Liquid restaking tokens (LRTs) from protocols like Renzo, Ether.fi, and Puffer add a liquidity layer on top of restaked positions, letting users trade or use restaked ETH in DeFi. The key risk is compounding slashing: restaked ETH can be slashed by Ethereum’s consensus rules and by any AVS the operator has opted into, creating multiple simultaneous loss vectors. The restaking model is expanding beyond Ethereum. Symbiotic, Karak, and Babylon (for Bitcoin) are building competing restaking marketplaces. Introduction Ethereum’s shift to proof of stake in September 2022 created a pool of economic security: over 30 million ETH staked by validators who risk losing their deposit (slashing) if they behave maliciously. This security pool protects Ethereum, but it sits idle with respect to every other protocol. New protocols that need decentralized validation face a bootstrapping problem. An oracle network, a data availability layer, or a cross-chain bridge needs validators, and those validators need economic stakes large enough to make attacks unprofitable. Building this security from scratch is expensive. Each new protocol must attract its own set of stakers, issue its own token for staking rewards, and hope that enough capital commits to make the system secure. Restaking proposes a different model. Instead of building independent security, new protocols borrow it from Ethereum. Stakers who already have ETH committed to Ethereum’s consensus opt in to additionally securing other services. The same capital backs multiple protocols simultaneously. EigenLayer formalized this concept and built the infrastructure for it. This guide explains how restaking works, what EigenLayer introduced, and where the risks compound. How Ethereum staking works before restaking To understand restaking, start with what it extends. Ethereum validators deposit 32 ETH into a staking contract. In return, they earn rewards for proposing and attesting to blocks (currently around 3% to 4% annualized). If a validator acts maliciously (double-signing, proposing conflicting blocks) or goes offline for extended periods, a portion of their 32 ETH is slashed. This creates an economic security guarantee. Attacking Ethereum’s consensus requires controlling enough staked ETH that the cost of being slashed exceeds the profit from the attack. With over 30 million ETH staked (roughly $100 billion at mid-2026 prices), that threshold is prohibitively high. Liquid staking protocols like Lido (stETH) and Rocket Pool (rETH) added a layer on top.