Ethereum

Ethereum is a decentralized blockchain with a built-in virtual machine, the Ethereum Virtual Machine (EVM), that runs general-purpose programs called smart contracts. Its native currency is ether (ETH). It was proposed by Vitalik Buterin in 2013 and launched on 30 July 2015. Since September 2022 it has used proof of stake.¹

HistoryReport an error

Founding

Vitalik Buterin described Ethereum in a whitepaper circulated on 27 November 2013 and announced it publicly in January 2014.¹² Gavin Wood wrote the formal specification, the Yellow Paper, published on 1 April 2014.³ The founders also included Charles Hoskinson, Anthony Di Iorio, Mihai Alisie, Joseph Lubin, Amir Chetrit, and Jeffrey Wilcke.

A public crowdsale from 22 July to 2 September 2014 raised about 31,500 BTC, then worth about US$18 million.⁴ The network launched with the Frontier release on 30 July 2015.

The DAO and Ethereum Classic

The DAO, an investment fund run by smart contract, raised about 12.7 million ETH in 2016. On 17 June 2016 an attacker exploited a reentrancy bug and drained about 3.6 million ETH. On 20 July 2016, at block 1,920,000, the network hard-forked to return the funds to their owners. A minority that rejected the fork kept running the original chain, which became Ethereum Classic (ETC).⁵¹

Move to proof of stake

The Beacon Chain, a separate proof-of-stake chain, launched on 1 December 2020. On 15 September 2022, in an upgrade called the Merge, Ethereum's original execution chain switched its consensus to the Beacon Chain and stopped using proof of work. The change cut the network's energy use by about 99.95%.⁶ Staked ETH became withdrawable with the Shapella upgrade on 12 April 2023.¹

Rollup-centric roadmap

In October 2020 Buterin proposed that Ethereum scale mainly through layer 2 rollups, such as Arbitrum, rather than on the base layer itself.⁷ Later upgrades followed that plan. Dencun (March 2024) added "blobs", a cheaper data type for rollups (EIP-4844).⁸ Pectra (May 2025) raised blob capacity (EIP-7691) and let ordinary accounts delegate to smart contract code (EIP-7702).⁹ Fusaka (3 December 2025) introduced PeerDAS (EIP-7594), which lets nodes verify blob data by sampling it rather than downloading all of it.¹⁰

Fusaka also allowed blob capacity to be raised by small "blob-parameter-only" (BPO) forks without a full upgrade. BPO1 (9 December 2025) raised the target and maximum blobs per block from 6/9 to 10/15, and BPO2 (7 January 2026) raised them to 14/21.¹⁰

The next named upgrade, Glamsterdam, includes enshrined proposer-builder separation (EIP-7732) and block-level access lists (EIP-7928). It went live on the Sepolia testnet on 6 October 2026.¹¹ Its deployment to the Hoodi testnet, planned for 26 October, was postponed after auditors flagged risks to existing contracts in two of its proposals. As of 30 October 2026 it has no mainnet date.¹²

Exchange-traded products

The US SEC approved exchange rule changes for spot ether exchange-traded products on 23 May 2024.¹³ They began trading on 23 July 2024.¹⁴ On 6 October 2025 Grayscale's ether funds began staking, the first US-listed spot crypto ETPs to do so.¹⁵

TechnologyReport an error

Ethereum uses an account model. Externally owned accounts are controlled by private keys; contract accounts are controlled by their code. Every operation in the EVM costs gas, paid in ETH.

Since the London upgrade in August 2021 (EIP-1559), each block has a base fee that is burned and an optional priority fee paid to the block proposer.¹⁶ As a result ETH supply can shrink when network activity is high.

Consensus is Gasper, which combines the Casper FFG finality gadget with the LMD-GHOST fork-choice rule. Time is split into 12-second slots and 32-slot epochs. A node runs two pieces of software: an execution client (such as Geth, Nethermind, Besu, Erigon, or Reth) and a consensus client (such as Prysm, Lighthouse, Teku, Nimbus, Lodestar, or Grandine). Having several independent clients is a deliberate design goal.¹⁷

Protocol changes are proposed as Ethereum Improvement Proposals (EIPs) and agreed in public All Core Developers calls.¹⁸

Incidents and controversiesReport an error

• The DAO fork (2016). See above.
• Parity multisig (2017). In July 2017 a bug in the Parity wallet let an attacker steal about 150,000 ETH.¹⁹ In November 2017 a user accidentally triggered a second bug that froze about 514,000 ETH permanently.
• Bybit hack (2025). On 21 February 2025 attackers stole about US$1.5 billion in ETH and staked ETH from the exchange Bybit's Ethereum multisig cold wallet, the largest crypto theft on record. The FBI attributed it to North Korea.²⁰
• Staking centralization. A large share of staked ETH is held through a few liquid staking providers and exchanges, which raises concerns about concentration of validator power.

TimelineReport an error

See alsoReport an error

• Bitcoin
• Arbitrum

ReferencesReport an error