BlackRock's Bitcoin ETF, IBIT, is rapidly accumulating Bitcoin holdings and is projected to surpass Grayscale's GBTC in two weeks. Grayscale has been transferring Bitcoins for redemptions and may deplete its holdings in 14 weeks. BlackRock and Fidelity collectively own 379,151 BTC worth $26.3 billion for their spot Bitcoin ETFs. Bitcoin is the top cryptocurrency choice for BlackRock clients, with IBIT holdings reaching 243K BTC. BlackRock's ETF could hold more Bitcoin than Grayscale's GBTC soon if current trends persist.