Crypto Newbie / Simulators / MEV-Boost
MEV-Boost / Proposer-Builder Separation Auction
95% of Ethereum mainnet blocks are built by MEV-Boost. Specialised builders (BeaverBuild, rsync, Titan) construct profitable blocks filled with arbitrage + liquidation opportunities, then bid against each other to have a validator include their block. The validator picks the highest bid — getting the MEV revenue without having to extract it themselves. This simulator runs the auction math so you can see exactly how MEV-Boost democratises MEV revenue across all stakers.
MEV-Boost builders
| Builder | Capture rate (% of MEV) | Take rate (% kept vs bid) | Reliability |
|---|---|---|---|
| BeaverBuild | |||
| rsync | |||
| Titan | |||
| BloXroute | |||
| Manifold (newer) |
This block's opportunity
All builder bids
Each builder calculates how much MEV they can capture, keeps some as profit, bids the rest to the proposer. Highest bidder wins.
| Builder | MEV captured | Bid to proposer | Builder profit |
|---|---|---|---|
| BeaverBuild★ winner | 0.475000 ETH | 0.465500 ETH | 0.009500 ETH |
| rsync | 0.450000 ETH | 0.436500 ETH | 0.013500 ETH |
| Titan | 0.425000 ETH | 0.403750 ETH | 0.021250 ETH |
| BloXroute | 0.400000 ETH | 0.360000 ETH | 0.040000 ETH |
| Manifold (newer) | 0.325000 ETH | 0.276250 ETH | 0.048750 ETH |
Without MEV-Boost (solo block-building)
Solo-built block earns: 0.125000 ETH
Before MEV-Boost: who captured the MEV?
Pre-Merge (PoW Ethereum): miners with MEV-aware software (Flashbots PGA) captured ~$100M+/year of MEV. Solo miners without sophisticated infrastructure got nothing — their blocks were 'left on the table' for arb bots to exploit in the next block. Post-Merge but pre-MEV-Boost: same problem with validators. Sophisticated staking pools (Lido, Coinbase) ran their own MEV extraction; solo home stakers got ~15% of the available MEV via basic public-mempool inclusion.
How MEV-Boost democratises MEV
MEV-Boost is a sidecar process every validator can run. It listens to bids from multiple relays (Flashbots, BloXroute, Manifold, etc.) and presents the validator with just the highest bid amount + a block hash. The validator signs a header committing to use that block; relay reveals the contents; validator broadcasts. Validator gets the bid amount; specialised builders kept the rest as their fee for building the block. Adoption: 95%+ of Ethereum validators run MEV-Boost in 2026.
Builder economics — race to the bottom on take rates
Builders compete for proposer attention. Their bid = (MEV captured) × (1 − take_rate). Lower take rate = higher bid = more likely to win, but smaller per-block profit. The market has converged to ~2-5% take rate for top builders. Why don't they go to 0%? Operating costs (servers, simulations, private order flow contracts) — bidding 100% of captured MEV would mean operating at a loss. The 2-5% margin is the equilibrium.
Why this matters for non-validators (DeFi users)
MEV-Boost's existence has a side effect: it CONCENTRATES MEV extraction in a few sophisticated builders. Sandwich attacks, arbitrages, liquidations — they all flow through these builders. This means the MEV ecosystem is now a more visible, more accountable game (you can trace which builder included which transaction in which block). It also means using protected RPCs (Flashbots Protect, MEV Blocker) — which route around the public mempool — is more effective than ever because the builders honoring those routes have explicit anti-sandwich commitments.
Frequently asked questions
+Is MEV-Boost the same as Flashbots?
Related but distinct. Flashbots is the company/research org that pioneered the MEV space and built the original mev-boost client. Other relays (BloXroute, Manifold, Aestus) implement the same protocol. MEV-Boost itself is open-source software validators run; Flashbots is one of multiple relays validators can configure it to listen to. Many validators run multiple relays simultaneously for resilience.
+Do solo home stakers really benefit?
Yes — significantly. A solo staker running MEV-Boost earns roughly the same per-block MEV revenue as Lido or Coinbase do. Average MEV bonus is ~0.05-0.15 ETH per block proposed — for a solo staker proposing ~2 blocks/year, that's 0.1-0.3 ETH = $350-1000/year of extra revenue on top of base staking rewards. Without MEV-Boost, a solo staker would earn ~15% of that.
+What's the risk of using MEV-Boost as a validator?
Relay trust. The relay sees the block contents before the validator signs the header. A malicious relay could (in theory) censor specific transactions or front-run the validator. Mitigation: validators run multiple relays + can fall back to solo block-building at any time. The 'censorship-resistant' relays (Manifold, Aestus) explicitly commit not to censor; mainstream relays (Flashbots, BloXroute) include all valid transactions including those from OFAC-sanctioned addresses (controversial topic with ongoing debate).
+What's PBS — is it different from MEV-Boost?
PBS = Proposer-Builder Separation, the GENERAL concept that block-building and block-proposing should be separate roles. MEV-Boost is the CURRENT IMPLEMENTATION of PBS on Ethereum (out-of-protocol, runs alongside the validator client). Ethereum researchers are working on 'enshrined PBS' that bakes the separation INTO the protocol itself, removing the need for trusted relays. Expected in a future hard fork (timeline uncertain, 2026-2027).
+How much MEV is there per block, realistically?
Highly variable. Median block: 0.02-0.05 ETH of MEV. Top 1% of blocks (DEX volatility spikes, big liquidations): 1-10+ ETH. Average annualised: ~0.10-0.15 ETH per block. Total annual MEV on Ethereum: $500M-1B+ depending on market activity. The simulator above lets you input typical and outlier opportunity sizes to see how proposer revenue varies.