Cardano Pulls Off Its First Hard Fork Without Dad — Van Rossem Goes Live 🗳️

Cardano's Van Rossem hard fork activated on Saturday, July 18, at 21:44 UTC, moving the mainnet to protocol version 11 and laying the technical and procedural groundwork for the Ouroboros Leios scalability upgrade targeted for late 2026. Onchain data from Cardanoscan shows the network advanced from protocol version 10 in epoch 643 to version 11 in epoch 644, at slot 192,844,800, after governance ratification on July 13.

The activation marks the first time in Cardano's history that a hard fork was initiated, debated and ratified entirely through the chain's onchain governance system rather than coordinated by Input Output, the engineering firm that designed and built the blockchain. Passage required sign-off from three separate bodies. Delegated representatives (DReps) approved the upgrade, with one tally showing 78.97% in favor against a 60% threshold; another reported 77.63%. Stake pool operators backed it at 52.7%, clearing the required 51%. The seven-member Constitutional Committee also found the proposal compliant, with all seven members agreeing where five were required.

The upgrade lowers smart contract execution costs and bundles technical changes including Plutus Cost Model enhancements, constant-time array indexing, native Value handling, faster list traversal, and new cryptographic primitives. Input Output's weekly development report said the release "lays the foundation for the next upgrade, the Dijkstra era hard fork, which will introduce Ouroboros Leios to Cardano." Van Rossem also adds a security fix requiring every stake pool to use a unique cryptographic key, closing a known attack path.

The fork is named after Max van Rossem, a Dutch Cardano contributor who passed away in October 2025 and who served as a developer, elected representative, node operator and constitutional delegate. Cardano has been building toward this governance model since the Chang hard fork in 2024, which introduced onchain voting, followed by the Plomin hard fork in early 2025, which gave ADA holders direct decision-making power.

For everyday users, nothing changes today: ADA transactions retain their existing shape, with the new cost reductions applying to Plutus smart contract execution rather than standard transfers. The picture around the activation is mixed: Cardano (ADA) traded at $0.158 on July 17, down 1.39% on the day, while derivatives traders pushed the long-to-short ratio to 0.48 and open interest climbed 4% to $421 million over the prior 48 hours, even as whale accumulation of ADA reached its highest level since 2023.