US Bitcoin spot ETFs hemorrhaged $333.6 million on May 26, roughly 4,320 BTC walking out the door in a single trading session. Ethereum spot ETFs joined the exodus with $35 million in net outflows on the same day, according to data from SoSoValue.
May’s rough ride in numbers
The May 26 outflow sits in the context of a month that has been consistently unkind to Bitcoin ETF holders. Earlier in the month, Bitcoin spot ETFs saw $635 million leave on May 13, followed by an even larger $649 million outflow on May 18. Then came a $105 million outflow on May 22. And now $333.6 million on the 26th.
The major issuers behind these products, BlackRock, Fidelity, and Grayscale, are the ones driving these flow dynamics. When their funds see coordinated outflows, it tends to ripple across the entire crypto market.
SoSoValue’s daily flow reports have become the go-to dataset for tracking these movements, offering granular visibility into how each issuer’s products are performing. The platform tracks flows across the full spectrum of US spot products, making it possible to identify whether outflows are concentrated in specific funds or spread broadly across the market.
What this means for investors
For Bitcoin specifically, the cumulative impact of multiple large outflow days in May creates genuine selling pressure. When ETF issuers process redemptions, they typically need to sell the underlying Bitcoin to meet those obligations. That means $333.6 million in outflows translates to real BTC hitting the market, roughly 4,320 coins that need buyers.
Multiply that effect across several outflow days, including the $649 million and $635 million sessions earlier in the month, and you’re looking at a substantial amount of supply being absorbed by the market.
For Ethereum, the $35 million outflow is smaller in absolute terms but carries similar implications. ETH products have struggled to match the inflow momentum that Bitcoin ETFs enjoyed earlier in their existence, and continued outflows only widen that gap.
The competitive landscape among ETF issuers adds another layer of complexity. BlackRock, Fidelity, and Grayscale are all competing for a shrinking pool of institutional interest. When overall flows turn negative, the battle shifts from attracting new capital to retaining existing assets under management.