# MEV Supply Chain Concentrates

The economics of proposer-builder separation keep pushing block construction toward a few integrated builders, making maximal-extractable-value capture a recurring threat to Ethereum's censorship resistance.

- Conviction: 40 / 100 (forming)
- Horizon: Emerging (watchlist)
- Tracking since: 2026-07-09T00:00:00.000Z
- Last updated: 2026-07-09T05:36:53.582Z
- Canonical: https://polylog.news/crypto/trends/mev-builder-centralization
- Publisher: Polylog
- Affected regions: Global

## Recent evidence

- [confirms] Ethereum Researchers Warn Block Builders Can Quietly Steal Searchers' Trades (2026-07-09): Ethereum researchers warned that under proposer-builder separation a single builder sees every bundle and can replicate a profitable searcher trade instead of honoring it, per the edition. This documents a concrete extraction mechanism that rewards builder concentration, reinforcing that PBS economics keep threatening censorship resistance.