Spot Bitcoin ETFs Draw $999M, Their Biggest Day Since October 2025

US spot bitcoin ETFs took in $999 million on Monday, 21 September, their largest single day since October 2025. BlackRock's IBIT led with $381.4 million, according to the Farside table published after the close. ARK and 21Shares' ARKB added $289.1 million and Fidelity's FBTC $238.8 million. The Block and CoinDesk give the total as $998.95 million and Cointelegraph as $998.9 million, so the tallies agree to within rounding. It was the third inflow day in a row.

Seven funds, no outflows

Every fund that moved on Monday moved in. Behind the top three came Morgan Stanley's MSBT with $61.7 million and Bitwise's BITB with $21.6 million. Grayscale's GBTC and BTC added $3.3 million and $3.1 million. The run started on Thursday with $159.5 million, followed by a $433 million Friday that left last week barely positive. The three days add up to about $1.59 billion, the "nearly $1.6 billion" Crypto Briefing cited on Tuesday morning. Earlier in the week the picture was the reverse. Farside shows $450.4 million leaving on 15 September and $295.9 million on the 16th. Ether funds had their own strong day. The Block counts $269.98 million of ether ETF inflows, the most since 7 October 2025, and a KuCoin flash citing SoSoValue puts $110 million of it in BlackRock's ETHA.

How big a day it was

The comparison point is 6 October 2025, when $1.2 billion arrived in one session, according to The Block and Cointelegraph. CoinDesk ranks Monday as the ninth-largest day since the funds began trading in January 2024. The Block's headline calls it the largest in 11 months and Bloomingbit's the biggest in 12. Both describe the same gap of just under a year. Within 2026, the previous high was $844 million on 14 January, Cointelegraph reported. That is also why the $730.9 million taken on 4 September had been billed as the biggest day since January.

The year is still in deficit. CoinDesk puts spot bitcoin ETFs down $450 million on a year-to-date basis. Cointelegraph counts $464 million of net outflows. The two figures do not reconcile, and neither outlet says which day its count runs to.

A high that depends on who measured it

The Block had bitcoin peaking near $87,300 on Monday, its highest since January. Cointelegraph says it briefly topped $87,200, and Crypto Briefing says it passed $87,000. CoinDesk's report names $85,000 as the level that marked the high since January. By 3 a.m. New York time on Tuesday the price was about $85,400, up 4.7% in 24 hours, The Block said. Cointelegraph had $85,430. KuCoin's daily report, taken at a different hour, showed $86,612. The same report counts about $648 million of short positions liquidated over 24 hours. We found that figure in no other account.

"While there is no single clear catalyst, the move appears to reflect a combination of renewed risk appetite, strong spot ETF demand and some short covering after bitcoin broke above key technical levels," Min Jung of Presto Research told The Block.

KuCoin's report ties the move to falling oil prices and Treasury yields, with the US 10-year yield slipping below 5%. Cointelegraph quotes CryptoQuant's Julio Moreno as saying bitcoin has moved above its 365-day moving average, which he treats as the final signal of a new bull market. That is his reading of one indicator.

The deficit after one good day

One session of this size still leaves the year short. Both year-to-date counts are smaller than Monday's inflow alone, so a repeat would close the gap. Tuesday's flows had not been published at the time of writing. Farside's table after the US close will show whether the streak reached a fourth day.