US mocks bitcoin and ether exchange-traded funds lost a combined $582 million in net outflows on Monday, the most since Nov. 20, as crypto markets tumbled, sending bitcoin to as low as $85,100.
Bitcoin ETFs recorded $357.6 million in outflows, the most in nearly two weeks, with ether ETFs seeing $224.8 million exits in a third day of withdrawals, according to Farside data.
According to Velo data, Monday is the third-worst performing weekday for bitcoin over the past 12 months, behind only Thursday and Friday in terms of average returns. Throughout 2025, several of bitcoin’s major local lows have occurred on Mondays, a pattern highlighted in the chart below.
A key level to monitor for potential bitcoin support is the US ETF cost basis. This metric represents the average entry price of bitcoin held by spot ETFs and is calculated by combining daily ETF inflows with the price of bitcoin at the time of each deposit to form a running average.
The total cost basis for U.S. bitcoin ETFs is currently near $83,000, according to Glassnode data, a level from which bitcoin has rebounded from prior lows on Nov. 21 and Dec. 1.
Among BTC ETFs, Fidelity Wise Origin Bitcoin Fund (FBTC) suffered $230.1 million in redemptions. Bitwise Bitcoin ETF (BITB) and ARK 21Shares Bitcoin ETF (ARKB) had notable outflows of $44.3 million and $34.3 million, respectively. BlackRock’s iShares Bitcoin Trust (IBIT) reported no net flows on the day, according to data from Farside.
In contrast, the iShares Ethereum Trust (ETHA) accounted for the majority of redemptions from ETH ETFs, at $139.1 million.
