BlackRock has made a significant investment in SPCX, purchasing $450 million worth of shares through its BIA fund. This move contributed to a dramatic increase in the number of ETF holders for SPCX, which rose from four to forty in a single day. The rapid adoption of SPCX by ETFs contrasts with the slower integration of stocks like META and BABA in the past, highlighting the shift towards active management in the ETF market. Currently, 60% of ETF products are actively managed, allowing for more flexible buying and selling strategies.