The first real test of how ETF investors would react to the largest crypto hack in history came back red. U.S. spot Bitcoin ETFs shed $643.2 million on Friday, according to Decrypt’s ETF tracker, their biggest single-day outflow of October. It was the funds’ first full session since attackers began draining roughly $6.4 billion from Binance at 4:05 p.m. ET Thursday, after U.S. markets had closed. Thursday’s $17.2 million in inflows predated the theft.