Ethereum's Glamsterdam Lands on Sepolia Oct. 6 — ETH Already Wearing the Crown on Hyperliquid 👑

The Ethereum Foundation confirmed Monday that the network's next major upgrade, Glamsterdam, will activate on the Sepolia testnet at epoch 353,024 on Oct. 6 at around 13:53 UTC. Sepolia node operators must update both their execution-layer and consensus-layer clients before the activation, the foundation said. Developers have not yet set dates for the validator-focused Hoodi testnet or for mainnet, and are targeting 2027 for the subsequent upgrade, Hegotá.

Glamsterdam combines the Amsterdam execution-layer upgrade with the Gloas consensus-layer upgrade. One of its headline changes is enshrined proposer-builder separation (ePBS), which moves the handoff between specialized block builders and validators into Ethereum's protocol, reducing reliance on outside middleware. The upgrade also introduces block-level access lists (BALs), which record the accounts and storage locations used during each block, and adjusts gas pricing to better reflect the cost of creating and accessing data on Ethereum. Contracts that rely on fixed gas stipends or hardcoded gas limits may require changes, the foundation said.

The Glamsterdam package is described as one of the largest L1 scaling upgrades since the Merge, with higher throughput and a redesigned gas market. Ethereum co-founder Vitalik Buterin said Sunday that Hegotá could be the network's last "normal" fork before development shifts toward recursive STARKs, automated formal verification, optimized consensus and quantum-safe cryptography.

Separately, on-chain data shows $ETH has overtaken $BTC in perpetual futures open interest on Hyperliquid as of Tuesday, a reversal that coincided with the Ethereum Foundation's date confirmation. The Glamsterdam activation on Sepolia is the first live test of the upgrade's combined execution- and consensus-layer changes before any Hoodi or mainnet rollout is scheduled.