Abu Dhabi's sovereign wealth fund Mubadala has disclosed its stake in iShares Bitcoin Trust (IBIT) worth $408.50 million, according to a 13F filing released today. The fund reported holding 8,726,972 shares of IBIT as of March 31, 2025, up from 8,235,533 shares reported at the end of 2024. Mubadala's significant move has breathed new life into US spot bitcoin ETFs, which saw significant inflows in May. Collective total inflows were $674.90 million, $425.45 million and $334.58 million on May 2, 5 and 9 alone, and continue to grow, including yesterday's $319.12 million inflow. BlackRock's bitcoin ETF IBIT remains the top choice for institutional investors, receiving $232.46 million in inflows yesterday alone.