Bitcoin (BTC) and Ethereum (ETH) have posted their worst first quarter performance in nearly a decade.Bitcoin's Q1 2025 performance was the weakest since 2018, with an 11.82% decline and negative returns in March.Ethereum's performance was even worse, with a 45.41% decline and negative returns for the past three months.Other altcoins, including meme coins, also performed poorly, with many down 80% from their all-time highs.