Largest daily total since October 2025 absorbs 11,530 BTC
US spot Bitcoin ETFs recorded $999 million in net inflows on September 21, marking their largest daily total since October 6, 2025, when they pulled in $1.2 billion. The single-day intake absorbed approximately 11,530 BTC as Bitcoin broke above $86,000.
BlackRock’s iShares Bitcoin Trust (IBIT) led the inflows with $381.4 million, followed by ARK 21Shares Bitcoin ETF (ARKB) at $289.1 million and Fidelity’s Wise Origin Bitcoin Fund (FBTC) at $238.8 million. These three products accounted for $909 million of the total, underscoring their dominance in the spot ETF market.
The $381 million inflow to IBIT ranked as its fourth-largest daily intake on record. The September 21 figure trails the largest one-day BTC intake recorded on November 11, 2024, when ETFs absorbed 12,560 BTC.
Secondary-market trading volume reached $4.5 billion on the latest session, described as relatively ordinary despite Bitcoin’s sharp price move and the large inflows. A separate session recorded $4.6 billion in trading volume.
Timing and attribution questions
Eric Balchunas, Senior ETF Analyst at Bloomberg Intelligence, cautioned that much of Monday’s inflow likely reflects Friday activity reported with a lag. “Look for more tonight,” Balchunas said, signaling continued inflow momentum.
The uneven pattern of recent creations reflects dispersed investor activity rather than single-institution allocations, according to Balchunas. The lag between trading activity and inflow reporting complicates direct attribution of the September 21 total to Bitcoin’s breakout above $86,000.
Bitcoin briefly traded above $87,000 during the period, though the exact timing of the price movement relative to ETF creation recording remains unclear.
