BlackRock’s iShares Bitcoin Trust has topped $90 billion in assets under management, vaulting the 19-month-old fund into the ranks of the 20 largest exchange-traded funds in the United States. The rapid ascent underscores the pace at which institutional investors have embraced spot Bitcoin products since they debuted last year. Industry-wide, spot Bitcoin ETFs now control about 1.296 million BTC valued at roughly $160 billion, equivalent to around 6.5 percent of the cryptocurrency’s circulating supply. Data compiled by WalletPilot indicate that, if current inflows continue, ETF holdings could exceed 1.5 million BTC by December, intensifying a supply squeeze already exacerbated by the April 2024 halving that cut daily issuance to about 450 BTC. Fresh regulatory filings highlight the breadth of demand. Hong Kong-based Avenir Tech reported owning 16.6 million shares of IBIT at the end of June, a stake worth more than $1 billion and accounting for 86 percent of its portfolio. The position adds to evidence that Asian investors are playing an expanding role in ETF inflows. The concentration of Bitcoin inside exchange-traded products is also changing the broader monetary landscape. River, a digital-asset firm, estimates Bitcoin now equals 1.7 percent of the world’s money supply, a record share that reflects the growing impact of ETF accumulation on both market liquidity and macro-level asset allocation.