For other altcoin-futures ETFs, the question is if the underlying coins will list on the CME, said Trey Griggs, US CEO of crypto trading firm GSR.
The bitcoin ETF eclipsed the prior record holder, the SPDR Gold Shares ETF, which hit $1 billion in assets in three days when it launched in 2004.
The overall demand for BITO was likely from a combination of investment advisors, private banking clients, and funds shorting the ETF, Vanda said.
Fundstrat's Tom Lee sees demand for the bitcoin futures ETF continuing, saying that it can get more than $50 billion in inflows in its first year.
The arrival of the bitcoin-futures ETF comes as bitcoin this year has moved above $1 trillion in market capitalization.