Bitcoin

The first and largest cryptocurrency by market capitalization, created in 2009 by the pseudonymous Satoshi Nakamoto. Bitcoin introduced the concept of a decentralized, peer-to-peer digital currency secured by proof-of-work mining. It has evolved from a cypherpunk curiosity to a trillion-dollar asset class, with proponents calling it "digital gold" and critics pointing to its energy consumption and price volatility. The supply is capped at 21 million coins, with periodic "halving" events that reduce the mining reward.