Jane Street boosts Fidelity Bitcoin ETF shares nearly 8x in Q3

Jane Street had a busy third quarter in Bitcoin ETFs. The trading giant grew its stake in Fidelity’s Wise Origin Bitcoin Fund (FBTC) nearly eightfold, while cutting its position in BlackRock’s iShares Bitcoin Trust (IBIT) by 19%.

The moves surfaced in Jane Street’s SEC 13F filing on November 12. That filing is a quarterly snapshot of what big money managers hold, and this one shows a firm rearranging the furniture rather than moving out.

The numbers behind the shuffle

Start with Fidelity. 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. The position’s value rose to $509.2 million, up from $45.3 million the prior quarter.

BlackRock’s fund went the other way, at least by share count. Jane Street reduced its IBIT holdings to 20,221,140 shares from 24,878,191, a 19% decrease.

The value of that IBIT position still grew, though. It rose to $957.3 million from $828.2 million, thanks to ETF prices climbing during the quarter.

The reshuffle did not stop at Fidelity and BlackRock. Jane Street picked up nearly 9 million shares of the ARK 21Shares Bitcoin ETF (ARKB), valued at around $249 million.

It also more than doubled its stake in BlackRock’s iShares Ethereum Trust (ETHA). That position now sits 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.

From IBIT’s top holder to spreading the bet

The IBIT trim stands out because of what came before it. At the end of Q2, Jane Street was the largest reported institutional holder of IBIT.

It got there after a 324% surge in its IBIT share count during that quarter. So the Q3 cut follows a period of aggressive accumulation, not a long, quiet hold.

IBIT itself remains the heavyweight among spot Bitcoin ETFs. The fund manages around $56 billion in total net assets as of mid-November 2026, the largest asset base in the category.

Jane Street was not the only big name adjusting its exposure. JPMorgan increased its stake in IBIT, a reminder that large institutions are not all moving in lockstep.

One important caveat applies to all of this. The filing reflects positions as of September 30, 2026, and does not capture any trading Jane Street did afterward.

What this means for Bitcoin ETF watchers

Context matters when reading Jane Street’s filings. The firm is a major electronic market maker and an authorized participant in various Bitcoin ETFs.

Authorized participants are the firms that help create and redeem ETF shares, keeping a fund’s price close to the value of what it holds.

That role complicates any simple reading of the numbers. Some of these positions may reflect inventory tied to market making rather than a straightforward directional view on Bitcoin.

The shift away from concentrating in IBIT is also worth watching. Moving from being IBIT’s largest reported institutional holder to spreading exposure across FBTC, IBIT and ARKB looks like diversification across issuers.

For Fidelity and ARK 21Shares, that is a nice vote of attention 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.

Investors comparing notes should also keep JPMorgan’s contrasting IBIT increase in view. When two large institutions move in different directions on the same fund, it tends to signal varied strategies rather than a single consensus trade.