The Bitwise Bitcoin ETF added 249.59 BTC, representing a computed flow of $21.47 million, on Monday, September 21. The print ranks well below the fund's most significant extremes seen during its stored history. Data for the week comes from issuer feeds for Bitwise Bitcoin ETF holdings and the iShares Bitcoin Trust holdings.
From the data
Spot BTC & ETH ETF Flows & Holdings
BITB's Notable Print
Monday's addition of nearly 250 Bitcoin brought BITB's holdings to 38,398.18 BTC. That's a $21.47 million computed flow at the XOOMAR mark, which is a routine positive print. The tape shows it's not a standout event.
The fund's most substantial positive inflow was $237.90 million. A single extreme negative print, -$280.70 million, represents the largest magnitude outflow. By both measures, Monday's flow is a middle-tier movement. The fund's position as the latest snapshot involves a net accumulation of 645.61 BTC from its first stored row through Monday.
A Three-Act Tape
The fund's recent history breaks into three distinct phases, according to a XOOMAR reading of the data. These are accumulation into new holdings, a washout period featuring the largest negative flow, and a recovery.
BITB hit its current holdings peak of 38,398.18 BTC exactly on Monday, September 21. The washout phase was marked by the day's most extreme outflow, a -$280.70 million single-session withdrawal. The recovery phase, ending Monday, has also featured the tape's top positive inflow of $237.90 million. Cumulatively, the fund has absorbed $2.58 billion in net positive flow through its stored sessions.
The table below shows a condensed version of the full tape for context.
| Ticker | Issuer | As-of date | Holdings | Computed flow | AUM |
|---|---|---|---|---|---|
| BITB | Bitwise | 2026-09-21 | 38,398.18 BTC | $21.47 million | $3.30 billion |
| ETHW | Bitwise | 2026-09-21 | 111,266.86 ETH | $4.32 million | $305.71 million |
ETHW's Quiet Streak Ends
Bitwise's Ethereum ETF, ETHW, also posted a flow on Monday. It was a $4.32 million inflow, lifting its total Ether holdings to 111,266.86 ETH. For ETHW, this mark ends a notable dry spell.
The fund had previously gone through a lengthy period with no activity in its stored data. The longest zero-flow streak lasted 15 stored sessions where the computed flow was $0.00. That stretch of inactivity has now been broken by two consecutive positive flow days, including the prior Friday's $1.32 million addition.
Waiting on BlackRock Data
The current tape offers only a first snapshot for BlackRock's iShares Bitcoin and Ethereum ETFs. IBIT and ETHA were first captured with a holdings dated 2026-08-17. With no prior row, their daily flow is absent.
The scale difference is stark. IBIT's first-snapshot pile of 790,775.59 BTC is 20.6 times larger than BITB's current holdings. Similarly, ETHA's 3,553,814.34 ETH is 31.9 times larger than ETHW's stash. Combined, the two iShares funds hold 829,173.77 BTC and 3,665,081.20 ETH across both asset classes.
How the Tape Is Compiled
The computed flow is derived from the change in holdings between two consecutive issuer as-of dates for each ETF. The delta in coins (BTC or ETH) is multiplied by the XOOMAR spot mark at the time the data is ingested. This yields a dollar value for the implied net flow into or out of the fund. AUM is simply the holdings at a given snapshot times the same mark. A missing flow value indicates a first snapshot, not a zero-dollar trade day.
Contextual Marks
Related spot markets provide context for the ETF's AUM valuation. Caution: the following perpetual futures marks are from a separate Pulse tape and should not be interpreted as caused by the ETF flows.
| Asset | Exchange | Mark | Funding rate |
|---|---|---|---|
| BTC | Binance | $86,122.73 | 0.00005269 |
| BTC | Bybit | $86,128.35 | 0.00006232 |
| ETH | Binance | $2,749.39 | 0.00008704 |
What Another Filing Would Show
The next major development for this tape will be a second holdings file from BlackRock's iShares for IBIT and ETHA. When those funds post a second as-of date, the lagging data gap will close, and the computed flow will populate for the market's two largest spot-ETF products. Their true daily rhythms will finally become visible. Until then, Monday's moves belong to the Bitwise suite.
Primary Sources & Disclosures
Disclaimer: Content on XOOMAR is produced using AI-assisted research, drafting, and verification workflows and is intended for informational and educational purposes only. It does not constitute financial, investment, legal, tax, medical, or professional advice of any kind. All analysis reflects available information at the time of publication and may not be current. Verify information independently and consult qualified professionals before making decisions. Editorial policy
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XOOMAR
Data desk
XOOMAR is a capital markets software and data company. Every brief on this site starts from a dataset the company collects itself from primary sources (CFTC, SEC EDGAR, FINRA, the Federal Reserve, exchange APIs) and names the numbers it is built on, with a link to the data page so you can check them. Briefs are reviewed before they go out and corrected in place when the data is revised.
