Key Insights:
- MicroStrategy (MSTR) stock holdings surged at Jane Street Group backing, despite the equity’s 20% monthly decline through early 2026.
- The trading firm reported 951,187 shares in its 13F filing for the fourth quarter of 2025, marking a 473% quarter-over-quarter increase.
- MSTR traded around $131 on February 23, while Strategy reported adding 592 Bitcoin to its treasury.
Jane Street Group disclosed a sharp increase in its MicroStrategy stock holdings in regulatory filings submitted on February 12, reporting 951,187 shares as of December 31, 2025.
The disclosure arrived as Strategy stock faced sustained pressure, with MSTR stock dropping roughly 20% over the prior 30-day window leading into early 2026.
Jane Street’s 13F filing for the quarter ended December 31, 2025, showed the position jumped, with multiple independent data providers confirming the share count.
MicroStrategy (MSTR) Stock in Focus
The firm added 785,224 shares during the fourth quarter of 2025, representing a 473% increase from the prior quarter. Yet, the absolute dollar value painted a more nuanced picture than the headline percentage suggested.
At current prices near $131 per share, the 951,187-share position implied roughly $125 million in common-share exposure. This figure remained modest relative to Jane Street’s broader portfolio, as the firm’s total 13F-reported market value was near $662 billion for the fourth quarter of 2025.
However, the $662 billion figure should not be used as a proxy for assets under management, as it included options positions and excluded cash balances, potentially distorting interpretations of trading firms’ reported values.
Jane Street’s filing also listed large options positions tied to MSTR, with the options lines including both calls and puts in a combined structure that suggested market-making activity rather than a simple directional bet.
Trading firms often carry equity inventory to hedge derivatives exposure, meaning a jump in the common-share line can accompany increased client activity in structured products rather than signaling a firm-wide bullish thesis.
Separately, Jane Street filed beneficial ownership reports showing it held 18,547,200 Strategy Class A shares, representing 6.9% of the company. Larger beneficial ownership figure exceeding the common-share line in the 13F due to reporting differences between filing types.
Beneficial ownership captures aggregate exposure across related entities, while the 13F common-share line represents a narrower slice of total positioning.
MicroStrategy Stock Filing Shows Quarter-End Snapshot Only
The December 31, 2025, snapshot predated recent price action, with MSTR trading near $131 on February 23, while Bitcoin hovered around $66,000.
The filing captured institutional positioning at year-end but did not reveal Jane Street’s current holdings or forward strategy, as firms can alter positions substantially between quarter-end and filing disclosure without triggering additional reporting requirements.
The lag between quarter-end and public disclosure creates interpretive challenges for investors parsing 13F data, who must distinguish between stale snapshots reflecting old conditions and live conviction signals that remain relevant to current market dynamics.
Strategy operates as a Bitcoin treasury company after legally changing its name from MicroStrategy to Strategy Inc on August 11, 2025, with the rebrand underscoring the company’s strategic pivot toward Bitcoin accumulation as its primary business model.
Strategy positions itself as the world’s largest corporate Bitcoin holder and reported adding 592 Bitcoin to its holdings last week.
The firm’s stock financing model drew particular scrutiny because Strategy funds purchase through equity issuance, convertible debt, and preferred instruments.
The structure works optimally when MSTR trades at a meaningful premium to net asset value.
However, when the premium compresses, capital-raising capacity shrinks, creating feedback loops during Bitcoin selloffs: falling Bitcoin prices pull down MicroStrategy stock, while falling MSTR reduces Strategy’s ability to fund new purchases at attractive dilution levels.
Bitcoin Proxy Trade Remains Active Despite Drawdown
Bitcoin sold off sharply into early February 2026 after declining from levels above $100,000 in December 2025.
The movement widened Strategy’s quarterly loss amid digital asset markdowns, as analysts linked the stock’s stress to Bitcoin volatility and broader crypto market outflows.
Investor sentiment around MSTR deteriorated alongside the Bitcoin drawdown, with the proxy trade amplifying moves in both directions as leveraged exposure meant sharper upside during rallies and steeper declines during selloffs.
Jane Street’s position increase occurred during that volatile period, suggesting institutional activity persisted despite drawdown conditions, even as options market structure played a meaningful role in the dynamics.
Large trading firms expand equity inventories to support derivatives flow and two-sided markets, with rising volatility often requiring larger hedging books to manage risk across client-facing derivatives products.
The regulatory filing confirmed institutional engagement with the Bitcoin proxy trade, though whether the position reflected conviction or flow mechanics remained structurally ambiguous by design.
13F filings do not disclose intent and capture only a moment in time without explaining the strategic rationale, while Jane Street’s large options footprint complicated any attempt at directional interpretation.
The December 31, 2025, timestamp also mattered because Bitcoin traded higher at year-end than in late February 2026, with MicroStrategy stock likewise facing less pressure in the fourth quarter of 2025 than in the following weeks.
Additionally, Strategy’s ability to fund future Bitcoin purchases depended critically on the stability of the equity premium.
A Closer Look into MicroStrategy’s Business
A compressed premium reduced the company’s capital-raising capacity, while an expanding premium reopened the funding channel and restored the business model’s core economics.
If the financing channel reopened, MSTR could re-accelerate Bitcoin accumulation and support the stock’s narrative as a leveraged Bitcoin proxy. On the other hand, a persistently compressed premium might transmit risk-off pressure back into Bitcoin sentiment through reduced corporate buying.
The institutional activity captured in Jane Street’s filing showed sophisticated players remained engaged with the trade even during periods of stress.
Yet the structure of that engagement, comprising common shares alongside large option lines, suggested nuance beyond simple bullish positioning.
For Bitcoin, the second-order implication centered on Strategy’s role as a major marginal buyer, with the company’s ability to continue accumulating dependent on equity market conditions as much as Bitcoin fundamentals.
Jane Street’s filing provided a snapshot of institutional positioning at year-end and confirmed that the firm’s footprint in the MicroStrategy stock complex grew amid elevated volatility.
However, the precise drivers behind that growth remained open to interpretation, given the market-making context.