Jane Street Sells 78% of Its MSTR and Bitcoin Holdings

Jane Street's latest 13F filing, covering positions as of March 31, 2026, shows the quant trading giant cutting back hard on the Bitcoin-related bets it built up in late 2025. Most coverage has framed this as routine market-maker inventory management. That's partly right, but it misses the more interesting shift sitting inside the options book.

Three big reductions stand out compared to the end of 2025. The iShares Bitcoin Trust (IBIT) position is down about 71%, from roughly 20.3 million shares to about 5.9 million shares (~$225 million). The Fidelity Wise Origin Bitcoin Fund (FBTC) position is down about 60%, to roughly 2 million shares (~$115 million). And Strategy (MSTR) common stock is down about 78%, from roughly 951,000 shares to about 210,000 shares (~$27 million). The MSTR cut is especially striking because Jane Street had increased that same position by 473% just one quarter earlier. So they bought heavily in Q4 2025, then sold most of it three months later.

At the same time, Jane Street rotated into Ether ETFs (roughly doubling its BlackRock Ethereum Trust position) and added to crypto-adjacent stocks like Coinbase, Galaxy Digital, and Riot Platforms, while trimming Bitcoin miners including IREN, Cipher Mining, TeraWulf, and Core Scientific.

Before reading these cuts as a bearish call, it's worth remembering what Jane Street actually does. It's not a long-term holder. It's a market maker and an Authorized Participant for most spot Bitcoin ETFs, meaning it creates and redeems ETF shares as client flows demand. ETF holdings on its 13F often function more like inventory than convictions. That's the standard explanation, and it covers most of the story. But it doesn't cover all of it.

The real story is in the options book. Jane Street still holds enormous options positions on Strategy: long puts (positions that gain if MSTR falls) worth $1.837 billion, equivalent to about 14.72 million shares, and long calls (positions that gain if MSTR rises) worth $1.604 billion, equivalent to about 12.85 million shares. Holding both is normal for a market maker. The interesting part is how those positions moved during the quarter.

• MSTR puts (long): 9.77M share-equivalent → 14.72M (+51%)

• MSTR calls (long): 18.55M share-equivalent → 12.85M (−31%)

• MSTR common stock: 951,187 shares → 209,833 (−78%)

So Jane Street sold most of its Strategy stock, cut its bullish call options by roughly a third, and added more than 50% to its bearish put options. The same pattern appears on IBIT. Common shares were cut by 71%, calls grew modestly, and puts rose sharply (an increase of roughly 12.5 million share-equivalent).

There are two reasonable ways to read this, and both are probably partly true. First, it could be hedging. Jane Street likely has offsetting positions that don't appear on a 13F (shorts, over-the-counter trades, swaps), and buying more puts may be balancing exposure that isn't visible. Second, there could be a defensive tilt. Even accounting for hedging, the direction of the shift, less stock, fewer calls, more puts, is the shape of a book that wants more downside protection than it had three months ago. Whether that reflects Jane Street's own view, client demand for protection, or both, the filing can't tell us. What's harder to defend is the "neutral straddle, profits from volatility either way" framing in some of the coverage. The book didn't stay balanced. It moved.

Two related controversies are worth knowing about as context. The "10 a.m. Bitcoin dump" theory has been circulating on social media, alleging coordinated selling around that time of day via ETF mechanics. And the bankruptcy estate of Terraform Labs has sued Jane Street, accusing it of trading on inside information during the 2022 TerraUSD collapse. Jane Street filed to dismiss in April and has denied the allegations. Neither claim has been proven, but they're part of why every Jane Street filing is being read so closely right now.

So three things are happening at once in this filing: inventory management, where some of the ETF cuts reflect normal market-maker flows; profit-taking, where they bought MSTR aggressively in Q4 2025 and sold most of it in Q1 2026; and a real shift toward downside protection in the options book on both MSTR and IBIT. Jane Street just posted record trading revenue of $16.1 billion for the quarter, so whatever they're doing is working. But "purely neutral inventory management" doesn't quite capture what the numbers show. The inventory shrank. The hedges grew. And on Strategy specifically, the hedges grew in the direction that pays off if things go down. That's not a prediction. It's just what the filing says, and it's the part most coverage is missing.

One caveat worth repeating: 13Fs only show long U.S. equity and options positions on one specific day. Shorts, futures, swaps, foreign holdings, and intra-quarter trading are all invisible. For a firm as active as Jane Street, this is one frame from a very long movie.