What is Ethereum (ETH)?

On July 30, 2015, a 21-year-old college dropout named Vitalik Buterin launched a blockchain that would eventually host hundreds of billions of dollars in financial applications, process more than a million transactions per day, and become the settlement layer for an entirely new financial system.

Ethereum took the core idea behind Bitcoin — an immutable, decentralized ledger — and asked a different question. Bitcoin proved you could send value without a bank. Ethereum asked: what if you could run any program without a company?

The answer was smart contracts. Self-executing code that lives on the blockchain, runs exactly as written, and cannot be altered or censored after deployment. Not by Buterin. Not by a government. Not by anyone. A lending protocol deployed on Ethereum in 2020 still runs today with zero human intervention — processing billions in loans, liquidations, and interest payments purely through code.

That's Ethereum's fundamental contribution: programmable trust. Bitcoin is a ledger that records who owns what. Ethereum is a global, shared computer that anyone can program — and that no one can switch off.

People call Ethereum the "world computer," and it's easy to dismiss that as marketing. It isn't. Ethereum really does behave like a single computer — one that happens to be running on roughly 900,000+ machines at the same time.

Here's the trick. Every validator node on the network runs the same piece of software, the Ethereum Virtual Machine (EVM). When you submit a transaction that calls a smart contract, every node executes the exact same code on the exact same input and must arrive at the exact same result. If even one node computed a different answer, the network would reject its version. This redundancy is the whole point: there is no central server to hack, bribe, or shut down, because there is no central server at all. The "computer" is the agreement of thousands of machines.

The EVM is Turing-complete, meaning it can run essentially any logic a normal computer can — loops, conditionals, math, data storage. Developers usually write contracts in a language called Solidity, which gets compiled down to EVM bytecode. That bytecode is what actually lives on-chain and executes.

Bitcoin and Ethereum share DNA — both are decentralized blockchains secured by cryptographic consensus. But they were engineered for fundamentally different jobs.

Bitcoin's scripting language is deliberately limited. It handles transfers and basic conditions (multi-signature wallets, timelocks) and stops there. The simplicity is a feature, not a bug — fewer moving parts mean fewer attack surfaces. Bitcoin does one thing and does it well: store and move value. There's also a hard cap of 21 million BTC, baked in forever.

Ethereum's EVM is Turing-complete. Developers can write virtually any logic: lending markets, decentralized exchanges, identity systems, prediction markets, games. The EVM executes that logic identically across roughly 900,000+ validator nodes worldwide. Bitcoin's blockchain records who sent money to whom. Ethereum's blockchain records that — plus the state of every smart contract, every token balance, and every decentralized application running on the network simultaneously. And unlike Bitcoin, ETH has no fixed supply cap; its issuance is governed by protocol rules that can even make it deflationary (more on that below).

The other structural difference is consensus. Bitcoin still uses Proof of Work, consuming roughly 150 TWh of electricity per year by burning computation. Ethereum switched to Proof of Stake on September 15, 2022 — an event called The Merge — and cut energy consumption by about 99.95% overnight. Validators now lock up 32 ETH as collateral and get penalized ("slashed") for misbehaving, instead of running power-hungry mining rigs.

To use Ethereum without hand-waving, you need to know there are exactly two kinds of accounts on the network.

• Externally Owned Accounts (EOAs) — these are controlled by a private key. Your wallet is an EOA. It can hold ETH, send transactions, and trigger contracts. There's no code attached; a human (or their key) drives it.
• Contract Accounts — these are controlled by their own code, not a key. A contract account holds ETH and data, but it only acts when an EOA (or another contract) calls it. Deploy a smart contract and you've created one of these.

Everything on Ethereum starts with an EOA signing a transaction. That transaction is a signed instruction — "send 1 ETH to this address," or "call the swap function on Uniswap with these parameters." Validators pick it up, the EVM runs whatever code it triggers, and the resulting change to balances and contract data — the network's state — is recorded permanently. Ethereum is essentially one giant, shared state machine: each block is a step that updates the global state according to the transactions inside it.

This is why people say Ethereum tracks far more than balances. Bitcoin's state is basically "who owns which coins." Ethereum's state is every account balance plus the internal memory of every contract — the order books, loan positions, token registries, and NFT ownership records of thousands of applications, all updated block by block.

Running code on a computer shared by the entire world creates an obvious problem: what stops someone from deploying an infinite loop and freezing the network? The answer is gas.

Every operation the EVM performs has a fixed cost measured in gas units. Adding two numbers is cheap. Writing data to storage is expensive. A plain ETH transfer costs exactly 21,000 gas. A complex DeFi swap routing through three liquidity pools can burn several hundred thousand. Gas meters computation so that whoever uses the world computer pays in proportion to the work they impose on it — and an attacker trying to run forever simply runs out of gas and the transaction halts.

You don't pay in gas directly; you pay in ETH, priced per unit of gas. That price is quoted in gwei — one gwei is one-billionth of an ETH (0.000000001 ETH). The arithmetic is simple:

Since EIP-1559 (live since August 5, 2021), the gas price splits into two parts. The base fee is set automatically by the protocol based on how full recent blocks were, and it is burned — destroyed, removed from circulation forever. On top of that you can add an optional priority tip that goes to the validator to get included faster. When the network is congested, the base fee rises sharply; on a quiet morning a transfer might cost under a dollar, while during the Bored Ape Yacht Club mint in April 2022 fees briefly spiked above $400. The market for block space is real, and it clears in real time.

The burn has a second-order effect: when the network is busy enough that more ETH is burned than is issued as staking rewards, ETH's total supply actually shrinks. A fee mechanism doubles as a monetary policy.

Ethereum's history reads like a stress test of decentralized governance under pressure.

It started with an $18 million crowdsale in 2014 — ETH priced at about $0.31. The mainnet launched on July 30, 2015, and for the first time developers could deploy arbitrary programs on a public blockchain.

Then came the test. In June 2016, a reentrancy bug in "The DAO" — a decentralized investment fund — let an attacker drain 3.6 million ETH (about $60 million at the time). The community faced an impossible choice: accept the theft or rewrite history. They chose a hard fork, and Ethereum split into ETH and Ethereum Classic. It was messy, controversial, and arguably the most important governance decision in blockchain history — proof that "code is law" has limits when humans are in the loop.

The 2017 ICO boom turned Ethereum into a launchpad for thousands of token projects. ETH surged from under $10 to roughly $1,400. Most of those tokens went to zero. The infrastructure survived.

DeFi Summer 2020 changed everything. Compound's COMP token launch in June triggered a yield-farming frenzy. Uniswap, Aave, Yearn, and SushiSwap pulled billions onto Ethereum in months. Total Value Locked went from about $1 billion in June 2020 to over $100 billion by late 2021.

The Merge on September 15, 2022 was the engineering climax — switching the consensus engine of a multi-hundred-billion-dollar network from Proof of Work to Proof of Stake without a single second of downtime. Then in March 2024, EIP-4844 ("proto-danksharding") added cheap "blob" storage for Layer 2s and cut rollup fees by 10–100x. In 2024, spot ETH ETFs received SEC approval, opening a direct pipeline between traditional brokerage accounts and Ethereum. The 2025 Pectra upgrade pushed further — smarter EOAs, more blobspace for L2s, and streamlined validator operations.

DeFi is Ethereum's killer application. Uniswap has processed trillions in cumulative swap volume with no company operating the exchange. Aave has originated tens of billions in loans with no loan officer. MakerDAO maintains DAI — a decentralized stablecoin — backed by on-chain collateral that anyone can audit in real time. Tens of billions of dollars sit in Ethereum-based DeFi protocols, all governed by code rather than a back office.

NFTs established digital property rights. Ethereum's ERC-721 standard made it possible to prove ownership of a unique digital object on-chain. The speculative frenzy of 2021–2022 faded, but the infrastructure remains — and it's being repurposed for gaming assets, event tickets, domain names (ENS), and real-world asset certificates.

Layer 2 networks are where Ethereum's scaling story gets interesting. Instead of making L1 faster (which would sacrifice decentralization), Ethereum outsources execution to rollup chains — Arbitrum, Optimism, Base, zkSync — that batch hundreds of transactions into a single L1 proof. Users get sub-dollar fees and near-instant confirmations while still inheriting Ethereum's security. After EIP-4844, combined L2 activity routinely exceeds L1 in daily transactions.

Ethereum's bet is architectural: stay small, secure, and decentralized at the base layer, and let a constellation of L2s handle the throughput. Whether that "rollup-centric roadmap" pays off against monolithic high-speed chains like Solana is one of the most consequential open questions in crypto.

Ethereum is powerful, not perfect. Honest education means naming the trade-offs — and there are real ones.

• Base-layer fees and congestion. When demand spikes, L1 gas fees can make small transactions uneconomical. That's the deliberate cost of having ~900,000 nodes re-verify everything. L2s ease this, but they add their own complexity — bridging, withdrawal delays, and trust assumptions that vary by rollup.
• Smart contract risk. "Runs exactly as written" cuts both ways. If the code has a bug — like The DAO's reentrancy flaw — the bug runs exactly as written too. Billions have been lost to contract exploits. Immutable code means a vulnerability can't be quietly patched after funds are at stake.
• Irreversibility. Send ETH to the wrong address or approve a malicious contract, and there's no support line and no undo button. The same finality that prevents fraud also means your mistakes are permanent.
• The scalability bet is unproven. The L2-centric roadmap is ambitious but still maturing. Fragmentation across dozens of rollups, sequencer centralization, and competition from faster monolithic chains are genuine open risks, not settled questions.
• Volatility and macro sensitivity. ETH is not a stable asset. It swings hard with crypto sentiment, rates, and liquidity cycles. Programmable money doesn't mean predictable price.

ETH is one of the most traded crypto assets on earth, and GaiaEx supports it across spot and perpetual markets — all non-custodial. Your ETH stays in your MPC-secured wallet. No deposit into an exchange hot wallet, no counterparty exposure, no withdrawal queue.

For spot, you can accumulate ETH against USDC or USDT using limit orders (set your price) or market orders (immediate fill). For directional conviction, ETH perpetual futures let you go long or short with leverage — useful for hedging existing holdings or expressing a macro view on how supply dynamics (issuance vs. EIP-1559 burn) and L2 adoption play out over time.

The practical starting point: pick a small position size, watch how ETH behaves around macro events (FOMC meetings, CPI prints, major protocol upgrades, L2 adoption milestones), and build conviction before sizing up. ETH's volatility is both the opportunity and the risk — respect both sides, and never risk capital you can't afford to lose.