Validator

Validators are the people (and machines) keeping proof-of-stake blockchains like Ethereum, Solana, Cardano, and Polkadot running smoothly. They're the PoS equivalent of miners—but instead of burning electricity, they put up their own crypto as a security deposit.

On Ethereum, becoming a validator means staking 32 ETH (roughly $80,000-$120,000 depending on the price). Your validator software proposes and verifies blocks around the clock. Do it honestly and you earn rewards (currently around 3-5% APR). Act maliciously or go offline too much, and you face slashing—permanently losing a chunk of your staked ETH.

How validators get picked varies by chain, but it generally involves weighted randomness—the more you've staked, the more likely you are to be selected. Ethereum uses committees of validators who verify blocks, with a randomly chosen proposer for each one. This randomness keeps any single validator from dominating.

Running your own validator requires: the minimum stake, reasonably reliable hardware (a regular computer with solid internet works fine), near-constant uptime (offline validators miss rewards and can face penalties), and enough technical know-how to maintain the software. If that sounds like too much, liquid staking protocols like Lido and Rocket Pool let you earn validator-like rewards without running anything yourself.

The money side breaks down into: block rewards (newly created tokens), transaction fees (tips from users), and MEV—"maximum extractable value," which is profit from strategically ordering transactions. After hardware and electricity costs, net yields typically land in the 3-8% range depending on the chain and conditions.