A recent 13F filing submitted by Jane Street, a major quantitative trading firm, reveals substantial adjustments to its crypto-related holdings as of March 31, 2026. While some observers have characterized these moves as standard inventory management typical of market makers, the detailed data suggests a more pronounced strategic shift within the options book.
Significant Reductions in Bitcoin and MSTR Holdings
Compared to the end of 2025, three key positions showed notable decreases. The firm reduced its stake in iShares Bitcoin Trust (IBIT) by approximately 71%, dropping from roughly 20.3 million shares to about 5.9 million shares, equating to an estimated value of $225 million.
Similarly, the position held in Fidelity Wise Origin Bitcoin Fund (FBTC) decreased by around 60%, falling to approximately 2 million shares, valued at roughly $115 million. The most striking reduction was seen in MicroStrategy (MSTR) common stock, which saw a decline of about 78%. Jane Street trimmed its holdings from an estimated 951,000 shares down to around 210,000 shares, representing a value of approximately $27 million. This MSTR sale is particularly noteworthy because the firm had dramatically increased this specific position by 473% just one fiscal quarter prior.
Rotations Into New Crypto Assets
Despite the sell-off in major Bitcoin vehicles, Jane Street executed several rotations. The firm increased its exposure to Ethereum Exchange Traded Funds (ETFs), effectively doubling its position in BlackRock’s Ethereum Trust. Additionally, it bolstered holdings in other crypto-adjacent stocks, including Coinbase, Galaxy Digital, and Riot Platforms. Conversely, the filing showed reductions in stakes held in various Bitcoin mining companies, such as IREN, Cipher Mining, TeraWulf, and Core Scientific.
Analysis of Options Positions: The Downside Shift
While Jane Street’s primary function involves acting as a market maker and Authorized Participant for most spot Bitcoin ETFs—a role that often means its ETF holdings are viewed more as inventory than long-term conviction—the true focus appears to be the options book. On MSTR, Jane Street maintains massive option positions: long puts (which benefit if the stock price declines) valued at $1.837 billion (equivalent to about 14.72 million shares), and long calls (which profit if the stock increases) valued at $1.604 billion (equivalent to about 12.85 million shares).
The quarter-over-quarter movements in these options are highly revealing:
- MSTR Puts (Long): Increased by 51% (from 9.77 million share-equivalent to 14.72 million).
- MSTR Calls (Long): Decreased by 31% (from 18.55 million share-equivalent to 12.85 million).
- MSTR Common Stock: Declined by 78% (from 951,187 shares to 209,833 shares).
A similar pattern was observed with IBIT: common shares dropped by 71%, while the long put positions saw a sharp increase of roughly 12.5 million share-equivalent.
Interpreting the Portfolio Shift
Experts suggest two main ways to interpret this data: first, it may represent complex hedging activities; Jane Street could be balancing invisible positions—such as over-the-counter trades or swaps—that are not reported on a 13F. Second, and more compellingly, the overall shift suggests a defensive tilt. The combination of fewer shares, fewer bullish call options, and increased bearish put options indicates a greater desire for downside protection compared to three months prior.
It is critical to note that while Jane Street posted record trading revenue of $16.1 billion for the quarter, simply labeling this activity as “neutral inventory management” overlooks the directional changes: the firm’s visible inventory shrank, but its protective hedges expanded significantly, particularly in MSTR.
Important Contextual Caveats
Investors should be aware that 13F filings provide a snapshot of long U.S. equity and options positions on only one specific day. Trades involving futures, shorts, swaps, foreign holdings, or intra-quarter transactions remain invisible within the filing. Furthermore, two unrelated controversies have recently surrounded the firm: circulating social media theories regarding a “10 a.m. Bitcoin dump,” and a lawsuit from the bankruptcy estate of Terraform Labs accusing Jane Street of trading on inside information during the 2022 TerraUSD collapse. Jane Street has denied these allegations.
