Bitcoin dropped more than 4% to $77,994.96 on Friday as fears of a potential security breach at Binance unsettled cryptocurrency markets. Cryptocurrency firms, including Circle and Tether, froze a combined $2.54 billion linked to the suspected incident on Thursday. Arkham Intelligence identified nearly $6 billion across 55 wallet addresses potentially associated with the incident. Binance has not explicitly confirmed a hack and said an investigation was underway. A Binance spokesperson said customer funds remained safe.