According to SoSoValue data, on May 21, total net outflows from Bitcoin spot ETFs amounted to $100.8 million, marking the fifth consecutive day of net outflows; BlackRock’s IBIT saw single-day net outflows of $103.6 million, the largest outflow product for the day, while Ark 21Shares’ ARKB was the only product to record net inflows ($2.83 million).
Bitcoin Spot ETFs: IBIT led daily outflows, ARKB was the only net inflow
The confirmed Bitcoin spot ETF fund flows for May 21 are as follows: BlackRock IBIT had net outflows of $103.6 million on the day, and its historical cumulative net inflows remain at $64.842 billion. Ark 21Shares ARKB was the only net inflow product for the day, with net inflows of $2.8287 million, bringing its historical cumulative net inflows to $1.282 billion. Fidelity FBTC, Bitwise BITB, Invesco Galaxy BTCO, VanEck HODL, and Grayscale GBTC recorded no fund flows on the day.
Before the May 22 press time, the overall market indicators for Bitcoin spot ETFs were: total net asset value (AUM) of $101.058 billion; ETF net asset ratio (ETF market capitalization as a share of total Bitcoin market cap) of 6.49%; and historical cumulative net inflows of $57.189 billion.
Ethereum Spot ETFs: ETHA led outflows, ETHB and ETHW recorded net inflows against the trend
The confirmed Ethereum spot ETF fund flows for May 21 are as follows: BlackRock ETHA had net outflows of $38.0076 million on the day (the largest outflow), and ETHA’s historical cumulative net inflows were $11.629 billion. BlackRock’s Staked ETH ETF (ETHB) had net inflows of $3.2936 million on the day, and ETHB’s historical cumulative net inflows reached $518.0 million. Bitwise ETHW recorded net inflows of $2.1371 million on the day, and ETHW’s historical cumulative net inflows were $384.0 million.
Before the May 22 press time, the overall market indicators for Ethereum spot ETFs were: total AUM of $12.211 billion; ETF net asset ratio (ETF market capitalization as a share of Ethereum total market cap) of 4.73%; and historical cumulative net inflows of $11.622 billion.
Snapshot of the current scale of the three types of spot ETFs (as of May 22)
BTC spot ETFs: total AUM $101.058 billion; net asset ratio 6.49%; historical cumulative net inflows $57.189 billion
ETH spot ETFs: total AUM $12.211 billion; net asset ratio 4.73%; historical cumulative net inflows $11.622 billion
SOL spot ETFs: total AUM $997.0 million (approaching the $1 billion mark); net asset ratio 1.97%; historical cumulative net inflows $1.125 billion
FAQ
Does IBIT’s daily outflow of $104 million mean BlackRock is reducing its Bitcoin holdings?
IBIT’s fund flows reflect ETF investors’ subscription and redemption behavior, not BlackRock’s own Bitcoin-position decisions. When IBIT records net outflows, it means that investors redeeming IBIT shares that day withdrew more funds than those adding new subscriptions. As the fund manager, BlackRock would sell an equivalent amount of Bitcoin to meet the redemption demand. IBIT’s historical cumulative net inflows still stand at $64.842 billion; the $104 million daily outflow is about 0.16% of the historical cumulative net inflows, and does not constitute a signal of systemic divestment.
Why did the SOL spot ETF record net inflows against the trend on the same day when both BTC and ETH saw outflows?
As of May 22, the total AUM of SOL spot ETFs was $997.0 million, far smaller than BTC ETFs ($101.058 billion) and ETH ETFs ($12.211 billion). Therefore, the impact of daily capital fluctuations is relatively higher because it is influenced more by large subscriptions. A $3.8569 million daily net inflow is roughly equal to 0.39% of the total AUM of the SOL ETF; within the much larger BTC and ETH markets, it amounts only to a marginal scale. Currently, the SOL ETF market has only one product, Fidelity FSOL, so market coverage and liquidity are relatively limited; individual institutional allocation actions can have a greater impact on the overall numbers.
Does the five-day consecutive net outflow break the historical precedent of Bitcoin ETFs?
In May 2026, before the five-day consecutive net outflows, Bitcoin spot ETFs had previously recorded strong net inflows of $2.13 billion in a single week, indicating that short-term investor sentiment among institutional capital can be more volatile. Consecutive five-day outflows are not uncommon in the historical records of Bitcoin ETFs: in 2025, there were also multiple instances of net outflows spanning several consecutive days, which were often followed by large weekly inflows. Currently, Bitcoin spot ETFs have historical cumulative net inflows of $57.189 billion and total AUM of over $100 billion, still at historical high levels. The five-day outflow event more likely reflects a cooling of short-term institutional sentiment rather than a structural withdrawal.
