Glossary · Crypto basics
What is Proof-of-stake (PoS)?
A consensus mechanism where validators are chosen to produce blocks based on how much native token they've staked as collateral. Cheating gets the stake slashed, replacing electricity-burning with capital-at-risk.
Last updated April 30, 2026
How it works
Validators on a PoS chain lock up the chain's native token as a security deposit. The protocol pseudo-randomly selects which validator proposes the next block, weighted by stake size. Other validators "attest" to the proposed block; once enough attestations stack up the block is finalized.
Two enforcement mechanisms keep validators honest:
- Slashing. Provably bad behavior (signing two conflicting blocks, going offline for extended periods) destroys part of the stake. Major slashings on Ethereum have been rare — typically tens of validators per year — but they're large enough (1+ ETH penalty plus exit) to deter the behavior.
- Reward forfeit. Idle or buggy validators just don't earn rewards, so over time they're outpaced by competitors and eventually leave.
Example
Ethereum requires 32 ETH per validator (~$108k at $3,400/ETH). The ~1M active validators secure the network at a current annualized issuance rate of ~3% APR on staked ETH. Validators that miss attestations lose a small per-slot penalty; ones that double-sign lose 1 ETH minimum plus immediate ejection from the validator set.
Solana's PoS doesn't have a hard minimum but real validators run hundreds of thousands of SOL each. The chain produces a block every ~400 ms with much higher hardware requirements (high-bandwidth servers, NVMe storage), which is one of the reasons its validator set is smaller than Ethereum's.
Why it matters
PoS replaced PoW on Ethereum in September 2022 (the "Merge"), and most chains launched since 2020 use it natively. The trade-offs versus PoW:
Wins:
- ~99.95% lower energy use
- Faster finality (Ethereum: ~13 minutes for absolute finality vs Bitcoin's hour)
- Lower issuance needed to secure the chain (Ethereum ~0.5%/yr issuance vs Bitcoin ~1.5%)
Concerns:
- Liquid staking via Lido has concentrated >30% of staked ETH at one provider, raising decentralization questions
- "Rich get richer" critique: stakers earn yield, which buys more stake
- Newer than PoW; less battle-tested
Most retail users participate by staking through a custodial provider (Coinbase, Kraken) or a liquid-staking protocol (Lido, Rocket Pool). Running a solo validator earns the highest yield but requires technical setup, the full minimum stake, and an always-on machine.