Over the past few days, US exchange-traded funds (ETFs) have significantly increased their Bitcoin holdings, with a total purchase of $654 million worth of Bitcoin in just three days. Major players in the ETF market, including BlackRock, Fidelity, Grayscale, and Bitwise, have collectively bought thousands of Bitcoin. BlackRock alone has accumulated 5,750 Bitcoin this week, contributing to its total ownership of 312,556 Bitcoin, valued at $18 billion. Specific purchases include BlackRock buying 3,320 BTC, Fidelity acquiring 1,100 BTC, and Grayscale adding 450 BTC. Additionally, US ETFs bought 5,528 BTC and 3,757 BTC on separate days. Notably, BlackRock's Bitcoin ETF had only one day of outflow. This surge in ETF inflows has triggered a market-wide rebound, indicating strong institutional interest in Bitcoin.