The Fulu Freeze: How Protocol Upgrades Broke MEV Competition for Seven Weeks
· 5 min read
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.