BlackRock's Bitcoin ETF, IBIT, has seen significant inflows of $2.8 billion recently, with Michael Saylor predicting it will become the world's largest ETF in a decade. Currently valued at $54 billion, IBIT's growth would require extraordinary daily inflows to surpass the Vanguard S&P 500 ETF's market cap of $593.5 billion. Analysts note an increase in the annualized basis trade for bitcoin ETFs, indicating a rising risk appetite among investors.