Jane Street sharply increased its stake in Fidelity's Wise Origin Bitcoin Fund in the third quarter while cutting its position in BlackRock's iShares Bitcoin Trust by 19%, according to the trading firm's latest 13F filing on November 12.
The filing, a quarterly snapshot of holdings by large money managers, showed Jane Street expanding its Bitcoin ETF exposure across several funds rather than concentrating it in a single issuer.
Fidelity position climbs
Jane Street held 886,736 FBTC shares at the end of June 2026. By September 30, that count had climbed to 7,010,008 shares, nearly an eightfold increase.
The value of the FBTC position rose to $509.2 million from $45.3 million in the prior quarter.
IBIT shares cut, value rises
For BlackRock's fund, Jane Street reduced its IBIT holdings to 20,221,140 shares from 24,878,191, a 19% decrease.
The value of the IBIT position still grew to $957.3 million from $828.2 million, as ETF prices climbed during the quarter.
The IBIT trim follows a period of aggressive accumulation. At the end of the second quarter, Jane Street was the largest reported institutional holder of IBIT, after its share count surged 324% during that quarter.
IBIT remains the largest spot Bitcoin ETF by total net assets, managing around $56 billion as of mid-November 2026.
Broader ETF reshuffle
Jane Street also picked up nearly 9 million shares of the ARK 21Shares Bitcoin ETF, valued at around $249 million.
It more than doubled its stake in BlackRock's iShares Ethereum Trust, with that position now at 7.83 million shares worth approximately $158 million.
Across FBTC, IBIT and ARKB, Jane Street's combined Bitcoin ETF holdings are now valued at approximately $1.79 billion.
Other large institutions were also adjusting exposure. JPMorgan increased its stake in IBIT, a contrast to Jane Street's reduction in the same fund.
Market-making caveat
Jane Street is a major electronic market maker and an authorized participant in various Bitcoin ETFs. Authorized participants help create and redeem ETF shares, keeping a fund's price close to the value of its holdings.
That role complicates a simple reading of the filing. Some positions may reflect inventory tied to market making rather than a straightforward directional view on Bitcoin.
The shift away from concentrating in IBIT also points to diversification across issuers. For Fidelity and ARK 21Shares, the increased attention comes from one of the most active players in the ETF ecosystem. For BlackRock, a 19% share trim from a top holder is a minor footnote given IBIT's roughly $56 billion asset base.
The filing reflects positions as of September 30, 2026, and does not capture any trading Jane Street did afterward.
