Bitcoin fell as much as 2.9% to approximately $81,600 as renewed doubts over artificial intelligence valuations weighed on risk assets and dragged Nasdaq futures lower. The broader crypto market followed suit, with the CoinDesk 80 Index declining 3.5%. DeFi tokens led the downside, with the DeFi index sliding 6%, outpacing losses across other crypto sectors. The pullback marked a sharp reversal in momentum for digital assets amid mounting caution toward technology-linked equities.