Ethereum
Ethereum is a decentralized, open-source blockchain platform that supports smart contracts and decentralized applications (dApps), with Ether (ETH) serving as its native cryptocurrency.
Ethereum was proposed in 2013 by Vitalik Buterin, a Russian-Canadian programmer who recognized that Bitcoin's scripting language was intentionally limited and that a more general-purpose programmable blockchain could unlock a far broader set of use cases. The Ethereum mainnet launched in July 2015. While Bitcoin is primarily designed to function as a peer-to-peer payment system and store of value, Ethereum was designed from the ground up as a programmable 'world computer' capable of executing arbitrary code on a decentralized network.
The defining innovation of Ethereum is the smart contract — self-executing programs stored on the blockchain that automatically enforce the terms of an agreement when predetermined conditions are met. Smart contracts operate deterministically: every node on the Ethereum network executes the same code and arrives at the same result, without any central party needed to arbitrate or execute the agreement. This enables trustless transactions: parties who do not know or trust each other can enter into binding financial agreements enforced entirely by code.
The ecosystem built on Ethereum's smart contract infrastructure is vast. Decentralized finance (DeFi) protocols — which recreate financial services like lending, borrowing, and trading without banks or brokers — are predominantly built on Ethereum. Non-fungible tokens (NFTs), which represent ownership of unique digital assets, are largely Ethereum-based. The token standard ERC-20 has enabled thousands of other cryptocurrencies and utility tokens to be built on top of Ethereum's infrastructure.
Ethereum underwent a landmark technical upgrade known as 'The Merge' in September 2022, transitioning its consensus mechanism from energy-intensive proof-of-work (like Bitcoin uses) to proof-of-stake. Under proof-of-stake, validators who wish to participate in transaction validation must lock up ('stake') 32 ETH as collateral. This transition reduced Ethereum's energy consumption by approximately 99.95% and introduced staking yields for validators — though it also changed the economic properties of ETH in ways that remain debated.
From a regulatory perspective, Ethereum and ETH have faced significant scrutiny regarding whether ETH constitutes a security under U.S. law. The SEC has investigated the question without issuing a definitive ruling, creating regulatory uncertainty that affects both retail investors and institutional adoption. Spot Ethereum ETFs were approved by the SEC in May 2024. As with all cryptocurrencies, investors should consider Ethereum a high-risk, speculative investment subject to significant price volatility, technical risk, and evolving regulatory treatment.