The Fulu Freeze: How Protocol Upgrades Broke MEV Competition for Seven Weeks
Two protocol changes hit Ethereum eight days apart in late 2025. The gas limit jumped from 45M to 60M on November 25. Then Fulu — Ethereum's PeerDAS upgrade — activated on December 3. Neither was unexpected. What nobody documented is what happened to MEV builder competition in the weeks that followed.
Builder bid density fell 66%. Proposers earned 30–40% less from MEV-boost during December. The market took seven weeks to recover, and when it did, the recovery was abrupt — not gradual. It happened in a single day.