BlackRock's iShares Bitcoin Trust took in roughly $665.16 million in net inflows on Monday, October 19, according to SoSoValue fund-flow data. The entire US spot Bitcoin ETF group pulled in about $526.6 million that day, which means IBIT alone covered the withdrawals from competing funds and then some. Monday's session reversed a Friday round of net outflows for the category.
The gap between IBIT and everyone else
Fidelity's FBTC lost about $83.6 million and Grayscale's GBTC shed roughly $54.9 million on the same day, per the same data set. Those aren't catastrophic numbers on their own, but they point to a familiar pattern: money rotating out of older or pricier products and into IBIT. The fund has become the default venue for investors who want Bitcoin exposure inside a brokerage account, and Monday's figure shows how lopsided that preference has become.
The concentration is worth flagging. When one fund's gross inflows exceed the net total for the whole category, the headline number is really a story about where capital lands, not how much fresh money is entering.
Why the flow data isn't a demand gauge
ETF flow figures track subscriptions and redemptions, not direct purchases of Bitcoin at a given hour. Fund mechanics and market-making activity can move the numbers without any new cash showing up at the underlying market. A large creation can reflect an authorized participant balancing inventory as easily as a pension fund taking a new position. So Monday's $665 million doesn't tell you anyone bought spot Bitcoin at 10 a.m. It tells you shares were created and redeemed in size.
That distinction matters more as IBIT grows. Single-day records get treated as sentiment readings, and they aren't built for that job.
The Friday-to-Monday swing
The category went from net withdrawals on Friday to a combined inflow above half a billion dollars on Monday. Two sessions do not make a trend, but the reversal is sharp enough that it'll be watched. Whether IBIT keeps absorbing the group's outflows depends on whether FBTC and GBTC redemptions continue at this pace — and on whether any other issuer can hold onto its base.
Next data point worth watching: Tuesday's flow prints, which will show if Monday was a one-off rotation or the start of a stretch.
