U.S. spot ETFs collectively hold about 1.296 million BTC as of August 13, equivalent to nearly 6.5% of the circulating supply. The past 30 days saw net additions of approximately 17,393 BTC across all funds, a run rate that, if sustained, would push total ETF holdings past the 1.5 million mark by December.
BlackRock’s iShares Bitcoin Trust accounts for the largest share, with roughly 744,500 BTC under management. This position represents about 3.3% of total Bitcoin supply and has been built since the fund’s January 2024 launch.
At an average pace of roughly 4,300 BTC added per month in recent months, IBIT alone could add around 130,000 BTC to its reserves by year-end if flows remain steady, further concentrating holdings within a single issuer.
In a flat inflow scenario at the current monthly average, ETFs would add approximately 70,000 BTC to cumulative holdings by year-end. For instance, if flows were to accelerate, doubling to around 34,000 BTC per month, ETF reserves could exceed 1.6 million BTC.
Such scenarios would deepen the impact on tradable supply, potentially increasing the price sensitivity to macroeconomic developments and fund-specific investor flows.
The next four months will determine whether spot ETFs cross the 1.5 million BTC threshold. At present rates, the milestone appears within reach, adding another layer to the interplay between institutional products and the underlying digital asset supply.
