Larry Fink, the co-founder, chairman and CEO of $10 trillion asset manager BlackRock, said he was "pleasantly surprised" at the retail response for his firm's spot bitcoin ETF and declared that he was "very bullish on the long-term viability of bitcoin."

Speaking to Fox Business' Charlie Gasparino and Liz Claman on Wednesday, Fink commented briefly on BlackRock's iShares Bitcoin Trust (IBIT), saying, "We would never have predicted it before we filed it that we were going to see this type of retail demand." 

"That surprised me how much [bitcoin has] gone up... We're creating now a market that has more liquidity, more transparency," said of being involved in bitcoin. 

According to The Block's bitcoin ETF data page, IBIT has accumulated $16 billion in assets under management and …