What Was “The DAO Hack” and What Were Its Consequences for Ethereum?
"The DAO" was an early, large-scale decentralized venture capital fund launched on Ethereum in 2016. A hacker exploited a "reentrancy" vulnerability in its smart contract code, draining over 3.6 million ETH, worth about $50 million at the time.
The incident was a major crisis for the young Ethereum network. To reverse the theft, the Ethereum community controversially decided to execute a "hard fork" of the blockchain, creating a new version of the ledger.
This led to a permanent split, resulting in two separate blockchains: Ethereum (ETH) and the original, unaltered chain, Ethereum Classic (ETC).