2018年に￥1,582,858でETH-USDを買っていたら...

Ethereum is a programmable blockchain launched in July 2015, proposed two years earlier by Vitalik Buterin. Where Bitcoin is designed primarily to move value, Ethereum runs smart contracts - code deployed to the network that executes exactly as written - which made it the settlement layer for most decentralised finance, stablecoins and NFTs. Ether (ETH) is its native asset and is used to pay for computation, priced in units called gas. In September 2022 the network completed 'the Merge', replacing proof of work with proof of stake and cutting its energy use by more than 99 percent. Like other crypto assets it trades continuously, so a year of ETH data holds roughly 365 observations rather than a stock market's ~252.

Ethereum launched in 2015 and drew its first wave of attention from the 2017 token-offering boom, which it largely powered. The 2016 DAO hack led to a contentious fork that split the chain into Ethereum and Ethereum Classic - a reminder that this is governed software, not a fixed instrument. The 2020-2021 period brought decentralised finance and NFTs, pushing network fees to levels that made small transactions impractical and driving activity toward competing chains and layer-2 rollups. The Merge in September 2022 moved the network to proof of stake, and subsequent upgrades reduced rollup costs. US spot ETFs were approved in 2024. Ether has no splits or corporate actions, so historical prices require no adjustment.

Ethereum rewards and punishes timing differently from Bitcoin, because its price has tracked cycles of actual network usage - token offerings, DeFi, NFTs - as much as broad crypto sentiment. Running the same entry year against both assets is the quickest way to see how much of a 'crypto' return was really an Ethereum-specific story.