Eight U.S. spot bitcoin ETFs added 12,073 BTC ($590 million) on 13 February, while Grayscale lost just 1,147 BTC ($56 million), according to Lookonchain monitoring. BlackRock's iShares Bitcoin ETF added 7,497 BTC ($366.5 million) and Fidelity added 3,039 BTC ($148.5 million).