A nine-day Bitcoin ETF inflow streak broke on the same day Ethereum funds posted their best session in ten months, with BlackRock on both sides of the split.
U.S. spot Bitcoin exchange-traded funds recorded a net outflow of $201.8 million on Friday, , ending a nine-session run that had pulled in more than $3 billion. On the same trading day, U.S. spot Ethereum ETFs took in a net $225.8 million, their strongest single session in ten months, stretching their own inflow streak to nine sessions and $1.42 billion. Both moves happened while Bitcoin and Ethereum prices fell together during a broader risk-off session.
The Bitcoin outflow was concentrated rather than broad-based. ARK 21Shares' ARKB lost $114.9 million, Bitwise's BITB lost $49.7 million, and BlackRock's IBIT saw $33.4 million in outflows. Morgan Stanley's Bitcoin Trust was the lone offset, taking in $9.3 million. Even after Friday, Bitcoin ETFs were still net positive by $3.3 billion for August with one trading session left.
Ethereum funds moved the other way. BlackRock's ETHA fund alone accounted for $1.02 billion of the nine-session, $1.42 billion inflow streak, or 72 percent of the total, and posted net inflows on every day of the run.
That creates a notable split inside the same asset manager's crypto ETF lineup. BlackRock's flagship Bitcoin fund lost assets on the same day its Ethereum fund helped carry the entire Ethereum ETF category to its best session in ten months.
The divergence is not enough to declare an institutional rotation from Bitcoin into Ethereum. Bitcoin's inflow streak was longer and larger heading into Friday, which made a one-day outflow more likely on its own. Ethereum could also be catching up after lagging Bitcoin's earlier run rather than directly receiving money pulled from Bitcoin funds.
The next several sessions of flow data will be the better test. If Ethereum keeps attracting money while Bitcoin remains flat or negative, the rotation argument gets stronger. If Friday proves isolated, the split will look more like a one-day divergence inside a broader risk-off move.