Proof-Of-Stake (PoS)
Last Updated: October 30, 2026
Quick Answer: Proof-of-stake (PoS) is a blockchain consensus mechanism in which validators lock up, or stake, the network’s own cryptocurrency for the right to propose and confirm new blocks. Honest validators earn rewards, while those who break the rules can lose part of their stake through a penalty called slashing. Ethereum, the largest PoS network, switched from proof-of-work to proof-of-stake in September 2022.
Key Takeaways
- In PoS, security comes from staked capital instead of the computing power and electricity used in proof-of-work mining
- An Ethereum validator needs 32 ETH; since the Pectra upgrade on May 7, 2025, one validator can hold up to 2,048 ETH
- About 43.9 million ETH, or 35% of supply by ethereum.org’s count, was staked when its staking page was read on October 30, 2026, with a current APR of about 2.5%
- The switch to PoS cut Ethereum’s electricity use by more than 99.988%, according to an estimate cited by ethereum.org
- Smaller holders can join through pooled or liquid staking and exchanges, but this adds third-party and concentration risks
How Proof-of-Stake Works
Proof-of-work (PoW) secures a blockchain by making miners compete to solve a puzzle that costs electricity; proof-of-stake replaces that race with a deposit. On Ethereum, as described on ethereum.org: NEM’s proof of importance (PoI) took a related approach, weighing both holdings and network activity.
- Staking. A user deposits 32 ETH into the deposit contract and runs software to become a validator.
- Proposing. Time is divided into slots of 12 seconds and epochs of 32 slots. In every slot, one validator is randomly selected to propose a block.
- Attesting. Other validators check the block and broadcast a vote, called an attestation, in its favor.
- Finality. When checkpoints receive votes representing at least two-thirds of all staked ETH, the blocks become finalized and cannot be reversed without destroying a large amount of stake.
- Rewards and penalties. Validators earn newly issued ETH and transaction fees for doing their job. Those who go offline lose small amounts, and those who act dishonestly, for example by signing two conflicting blocks, are slashed: part of their stake is destroyed and they are removed from the network.
Since the Pectra upgrade went live on May 7, 2025, EIP-7251 lets a single validator hold any amount between 32 and 2,048 ETH and earn rewards on the full balance, according to ethereum.org.
Proof-of-Stake vs Proof-of-Work
| Feature | Proof-of-Stake | Proof-of-Work |
|---|---|---|
| Who adds blocks | Validators chosen in proportion to stake | Miners who solve a hashing puzzle first |
| Main cost | Capital locked as stake | Hardware and electricity |
| Penalty for cheating | Stake can be slashed | Wasted electricity on rejected blocks |
| Energy use | Low; Ethereum about 0.0026 TWh a year | High |
| Examples | Ethereum, Solana, Cardano, Avalanche, Polkadot | Bitcoin, Litecoin, Dogecoin |
Proof-of-Stake Examples in 2026
Ethereum. Ethereum moved to PoS on September 15, 2022, in an upgrade known as The Merge. When read on October 30, 2026, the ethereum.org staking page showed about 43,948,738 ETH staked, 35% of supply by its own count, and a current APR of 2.5%. The page does not say when these figures were last refreshed. The Crypto Carbon Ratings Institute estimates that The Merge reduced Ethereum’s annual electricity use by more than 99.988%, to about 0.0026 TWh a year across the whole network, according to ethereum.org.
Liquid staking. Many holders stake through protocols that pool deposits and issue a tradable receipt token. Lido, for example, held about $21.7 billion in total value locked on October 30, 2026, according to DefiLlama. Those receipt tokens are widely used in DeFi and yield farming.
Other networks. Solana, Cardano, Avalanche, Polkadot, Cosmos and BNB Chain all use variants of proof-of-stake. Some let holders delegate tokens to a validator without giving up ownership.
Risks and Common Misconceptions
“PoS means the richest control the network.” Larger stakes earn proportionally larger rewards and more chances to propose blocks, so concentration is a real concern. The risk grows when a few staking providers or exchanges control a large share of the stake. Ethereum’s design limits the damage: changing finalized history would require controlling a large share of all staked ETH and would expose that stake to slashing.
“Staking rewards are risk free.” Rewards are paid in the network’s own token, whose price can fall. Validators can be penalized for downtime or slashed for mistakes. Staking through a third party adds smart contract, custody and counterparty risk, and unstaking can take time.
“PoS is less secure than PoW.” The two use different security models. Attacking PoW requires buying hardware and energy; attacking PoS requires acquiring a large share of the staked token, which an attacker would then risk losing.
Related Terms
Market data for Ether is on our Ethereum price prediction page.
Frequently Asked Questions
What is proof-of-stake in simple terms?
Proof-of-stake is a way for a blockchain to agree on new transactions. Instead of miners using electricity to solve puzzles, validators lock up the network’s coins as a deposit. The network picks validators to propose and check blocks, pays them for honest work and destroys part of their deposit if they cheat. Ethereum is the largest network using this system.
What is the difference between proof-of-stake and proof-of-work?
Proof-of-work secures a blockchain with computing power and electricity: miners compete to solve a puzzle, and the winner adds the next block. Proof-of-stake secures it with locked capital: validators stake coins and are chosen to add blocks, with slashing as the penalty for cheating. Bitcoin uses proof-of-work, while Ethereum has used proof-of-stake since September 2022.
How much ETH do you need to stake?
Running your own Ethereum validator requires 32 ETH, and since the Pectra upgrade in May 2025 a single validator can hold up to 2,048 ETH. Smaller holders can stake any amount through pooled or liquid staking services and centralized exchanges, with some pools accepting as little as 0.01 ETH. These options add third-party risk because someone else runs the validator.
What is slashing?
Slashing is the penalty a proof-of-stake network applies to a validator that breaks the rules, for example by signing two conflicting blocks. Part of the validator’s stake is destroyed and the validator is removed from the network. Slashing differs from the small penalties for being offline. It exists to make attacks expensive, because cheating puts the attacker’s own capital at risk.
Is proof-of-stake better for the environment?
Proof-of-stake uses far less energy than proof-of-work because validators do not compete with power-hungry mining hardware. The Crypto Carbon Ratings Institute estimates that Ethereum’s move to proof-of-stake cut its electricity use by more than 99.988%. Ethereum now uses about 0.0026 TWh a year across its entire global network, according to ethereum.org.
Data sources: ethereum.org (consensus, staking, Pectra, forks and energy pages, read October 30, 2026; staking figures not timestamped by the page), DefiLlama (Lido TVL, October 30, 2026).