How do MEV relays affect the rewards you actually receive?

11 November 2026

MEV relays act as intermediaries between block builders and validators, and they can significantly influence the staking/staking-tax-implications-guide/">staking rewards you earn by filtering out or including certain types of MEV opportunities. Your actual yield depends on which relay your chosen validator uses, how that relay prioritizes transactions, and whether the relay captures value that would otherwise go to you.

What MEV relays do

In proof-of-stake networks like Ethereum, validators propose blocks. Block builders compete to construct the most profitable blocks by ordering transactions in ways that extract Maximum Extractable Value (MEV) - profits from arbitrage, liquidations, or front-running. Relays connect these builders to validators, forwarding proposed blocks and their associated bids.

A relay’s role is not neutral. Each relay can decide which builders it accepts blocks from, what types of MEV it allows (or blocks), and how much of the builder’s bid it passes to the validator. That decision directly affects the reward you receive as a staker, because the validator’s earnings - after commission - flow to you.

How relays shape your rewards

Selection of MEV types

Some relays specialize in “ethical MEV” that avoids harmful front-running or sandwich attacks. Others accept all profitable MEV, including aggressive strategies. A validator using a relay that filters out high-MEV transactions will earn less per block than one using a relay that maximizes extraction. Over time, this difference compounds.

For example, a relay that permits only arbitrage and liquidations (which stabilize prices) may yield 10 - 20% less total reward per block than one that also allows sandwich attacks. The tradeoff is that the validator avoids contributing to harmful trading patterns, but your staking returns shrink.

Builder competition and bids

Relays receive block proposals from multiple builders, each offering a bid (the fee paid to the validator for including the block). The relay typically forwards the highest bid to the validator. However, some relays cap bids or reject blocks from builders with poor reputation or high failure rates. If a relay excludes the highest-paying builder, the validator - and you - get a lower bid.

The number of builders connected to a relay also matters. A relay with few builders has less competition, meaning bids tend to be lower. A validator using a relay with a large, active builder set sees higher average bids and therefore higher rewards.

Relay fees and censorship

Most relays are operated by for-profit entities. They charge a fee, usually a percentage of the bid, before passing the rest to the validator. This fee is invisible to you but reduces your net yield. Fees range from 0% to 10% of the bid, depending on the relay. You cannot see this directly in your staking dashboard - it’s baked into the reward amount.

Additionally, some relays censor certain transactions (e.g., those involving sanctioned addresses or specific protocols). If a relay blocks a high-value transaction, the builder may produce a less profitable block, lowering your reward. Censored relays can also reduce the validator’s overall profitability if they miss opportunities other relays capture.

How to assess which relay your validator uses

You cannot choose a relay directly when you delegate stake. Your chosen validator decides which relays to connect to. However, you can investigate:

1. Check the validator’s public profile. Many validators list their relay configurations on sites like beaconcha.in or in their staking pool documentation. Look for terms like “MEV-boost,” “Flashbots,” “bloXroute,” or “Eden Network.”

2. Compare reward rates. If your validator’s average reward per block is significantly lower than the network average, it may be using a relay that filters aggressively or charges high fees. Network average reward data is available on public dashboards.

3. Ask the validator operator. Validators who are transparent about their relay choices often publish this information. If they do not, consider that a red flag.

4. Monitor relay performance. Some relays publish historical data on average bid amounts and success rates. A validator using a relay with consistently lower bids will yield less over time.

The practical impact on your staking yield

The difference between a validator using a top-performing relay and one using a low-performing relay can be 5 - 15% of total rewards annually. For a staker with 32 ETH (a full validator), that could mean a gap of 0.5 - 1.5 ETH per year at current yield levels. For smaller stakes in a pool, the difference is proportional.

This variation is separate from the validator’s commission rate. A validator with a 5% commission using a good relay may still net you more than one with 0% commission using a poor relay. Always compare effective yield, not just commission.

Risks and Tradeoffs

• Relay centralization. Most validators use a small number of relays (often just Flashbots or bloXroute). If those relays go offline or change policies, rewards can drop suddenly. Diversification across relays reduces this risk but is rare.
• Relay failure or attack. A relay could be hacked or manipulated to forward fake blocks, though this is uncommon. The Ethereum protocol has built-in protections, but a malicious relay could still cause missed rewards.
• Regulatory pressure. Governments may force relays to censor transactions, potentially reducing your yield if your validator uses a compliant relay.

What you can do

• Review your validator’s relay settings before delegating. Favor validators that use multiple relays or publish their relay performance.
• Monitor your effective yield over weeks, not days. A single bad block is noise; a persistent gap is a signal.
• Consider using a staking pool that explicitly manages relay selection on your behalf, such as those that run their own relay or negotiate lower fees.

MEV relays are not a hidden fee. They are a structural part of how staking rewards are generated. Understanding which relay your validator uses - and why - helps you evaluate whether your yield is fair or if you could do better elsewhere.

Back to staking