Castle Island Ventures announced today that it is leading a $2.8 million pre-seed funding round for RockSolid, an Ethereum-based liquid staking protocol designed to deliver superior yields without the complexities of restaking.
The investment, which brings RockSolid’s total early-stage capital to over $3 million, will fuel the startup’s expansion of its core product: RockSolid ETH, a Layer-2 liquid staking token (LST) built atop the battle-tested RocketPool protocol. Unlike traditional LSTs that lock users into rigid structures, RockSolid ETH emphasizes “100% pure staking” with guaranteed, instant, and permissionless withdrawals, leveraging Ethereum’s upcoming Pectra upgrade for enhanced efficiency. The protocol promises better-than-market staking returns while maintaining low fees, positioning it as a go-to solution for yield-hungry investors navigating the post-Shanghai era.
“RockSolid is tackling one of the biggest pain points in Ethereum staking: balancing liquidity with real, risk-adjusted rewards,”
said Nic Carter, managing partner at Castle Island Ventures, a firm renowned for its early bets on blockchain primitives like Blockstream and OpenSea.
“In a world where restaking hype has introduced hidden risks and complexity, RockSolid’s focus on simplicity and purity is a breath of fresh air. We’re excited to back a team that’s engineering for the long haul.”
Founded in early 2025 by a quartet of ex-RocketPool contributors and DeFi engineers from ConsenSys, RockSolid aims to democratize access to high-yield staking. Its liquid vaults actively participate in incentivized campaigns, lending opportunities, and emerging DeFi protocols, all while sidestepping the slashing risks associated with aggressive restaking strategies. Early metrics show RockSolid ETH outperforming native ETH staking by up to 15% APY, with over $50 million in total value locked (TVL) achieved in private beta.
The round also attracted participation from a syndicate of strategic angels, including partners from Paradigm and Dragonfly Capital, as well as institutional backers like Electric Capital. Funds will primarily support protocol hardening, validator network growth, and integrations with major DeFi aggregators like 1inch and Yearn Finance.
This funding comes amid a resurgence in liquid staking adoption, with the sector’s TVL surpassing $40 billion across chains following Ethereum’s Dencun upgrade. RockSolid’s Ethereum-native approach differentiates it from cross-chain competitors like Kintsu (recently backed by Castle Island in a $4M seed for Monad-focused staking), emphasizing security over speculation.
“Staking shouldn’t feel like a gamble. Our mission is to make Ethereum’s proof-of-stake as seamless and rewarding as possible, empowering users to stay liquid while securing the network. With Castle Island’s guidance, we’re scaling to meet the demands of the next bull cycle.”
Elena Vasquez, RockSolid’s CEO and former RocketPool protocol lead
RockSolid plans to launch its public mainnet in Q4 2025, with a focus on institutional onboarding and cross-layer compatibility.
For more details, visit rocksolid.network.
About Castle Island Ventures
Castle Island Ventures is a Boston-based early-stage VC firm exclusively investing in public blockchain startups. With a portfolio spanning infrastructure, DeFi, and consumer crypto, the firm has backed category leaders like Blockstream, Coin Metrics, and River Financial.
About RockSolid
RockSolid is pioneering the next generation of liquid staking on Ethereum, offering high-yield LSTs with unmatched liquidity and security. Built for the Pectra era, it’s staking, simplified.
