Jane Street's $662B Q4 2025 Portfolio: When 15% of Your AUM Is in a Single ETF

Jane Street Group's Q4 2025 13F filing contains a number that stops you mid-scroll: $95.9 billion in SPY. That's 15.4% of the firm's $662.12 billion portfolio allocated to a single S&P 500 ETF. For a quantitative trading firm known for its mathematical precision, parking nearly one-sixth of assets under management in one instrument is either the most boring trade on Wall Street — or the most misunderstood.

TL;DR — Key Takeaways

• AUM reached $662.12B in Q4 2025, up 0.8% QoQ from $657.1B — and up 114% from $309.4B in Q3 2023
• SPY dominates at $95.9B (15.4%) — more than double the second-largest position
• Top-5 concentration at 37.8% is notably higher than comparable mega-filers, driven by SPY's outsized weight
• ETF + commodity positions total ~$145B: SPY, an unidentified ETF ($44.2B), GLD, IWM, SLV, and TLT
• NVDA ($37.9B) and TSLA ($36.2B) are the largest single-stock equity positions
• 17,120 positions — the highest position count among major 13F filers
• AUM has more than doubled from $309B to $662B in six quarters
• WhaleScore: 74.25 — reflecting massive capital deployment with moderate per-position concentration

Filing Snapshot

Metric	Value
Filer	Jane Street Group, LLC
CIK	0001595888
Report Date	Q4 2025 (December 31, 2025)
AUM	$662.12B
QoQ Change	+$5.0B (+0.8%)
Positions	17,120
WhaleScore	74.25
Top-1 Weight	15.4% (SPY)
Top-5 Weight	37.8%
Top-10 Weight	49.3%

The SPY Question: $95.9B in a Single ETF

The first thing anyone notices in Jane Street's filing is the SPY position. At $95.9 billion, it's larger than the market cap of most S&P 500 components. It's also more than double Jane Street's second-largest holding.

Context matters here. Jane Street is one of the world's largest ETF market-makers. The firm provides liquidity across thousands of ETFs, and SPY is the single most-traded security on earth by dollar volume. A $95.9B SPY position in a market-making context isn't a bet that the S&P 500 will go up — it's inventory. The firm holds SPY shares to facilitate creation and redemption, to hedge options exposure, and to maintain delta-neutral positioning across its massive derivatives book.

That said, 15.4% in one instrument is still a concentration risk worth noting. Even if it's hedged nine ways to Sunday, a flash crash or liquidity seizure in SPY would create meaningful mark-to-market exposure for the firm.

The ETF and Commodity Layer

Beyond SPY, Jane Street's portfolio reveals a deep commitment to ETF and commodity instruments:

• An unidentified ETF position: $44.2B (7.1%) — the second-largest holding, likely another index or sector ETF used in market-making operations
• GLD: $20.5B (3.3%) — gold exposure, potentially hedging or commodity arbitrage
• IWM: $15.6B (2.5%) — Russell 2000 exposure providing small-cap market-making inventory
• SLV: $6.7B (1.1%) — silver ETF, paired with GLD for precious metals strategies
• TLT: $6.0B (1.0%) — long-term Treasury bonds, providing rates exposure

Combined, these ETF and commodity positions account for roughly $145 billion — about 22% of total AUM. This is the infrastructure layer of a market-making operation: the raw materials Jane Street uses to provide liquidity and manage risk across asset classes.

Tech Underneath: The Real Equity Bets

Strip away the ETF layer and the equity portfolio comes into focus. The largest single-stock positions are concentrated in technology and AI:

• NVIDIA ($37.9B, 6.1%) — the largest pure equity position and a direct AI infrastructure play
• Tesla ($36.2B, 5.8%) — a massive position that reflects both options market-making demand and potential directional exposure
• Meta ($21.6B, 3.5%) — another AI beneficiary with heavy options activity
• Apple ($14.0B, 2.3%) and Microsoft ($10.9B, 1.8%) — mega-cap tech anchors
• AMD ($9.1B, 1.5%) — semiconductor exposure alongside NVIDIA

The tech cluster totals roughly $130 billion, making it comparable in size to the ETF layer. This dual structure — ETF infrastructure on top, concentrated tech underneath — is the defining feature of Jane Street's 13F profile.

The AUM Explosion: $309B to $662B

Perhaps the most striking data point in Jane Street's filing history is the AUM trajectory. In Q3 2023, the firm reported $309.4B. Six quarters later, that number has more than doubled to $662.1B — a 114% increase.

The growth hasn't been smooth. There was a pullback in Q2 2024 (down to $437.7B from $478.4B) and a sharper drawdown in Q1 2025 (down to $399.3B from $460.4B). But each dip was followed by an aggressive rebound: Q2 2025 saw a $106B jump to $505.6B, and Q3 2025 added another $151B to reach $657.1B.

This pattern — sharp drawdowns followed by larger recoveries — is consistent with a firm that's expanding its market-making capacity and capturing an increasing share of global ETF liquidity provision.

Frequently Asked Questions

Why does Jane Street hold $95.9B in SPY?

Jane Street is one of the largest ETF market-makers globally. SPY is the most liquid security in the world, and holding large inventory positions is essential for facilitating creation/redemption, providing continuous liquidity, and hedging the firm's derivatives exposure. The position size reflects the scale of Jane Street's market-making operations, not a directional bet on the S&P 500.

What is the unidentified ETF position at $44.2B?

The holding identified by CUSIP 04609e107 appears to be an ETF position. Without a confirmed ticker mapping, we can't identify it precisely. It's likely another major index or sector ETF used in Jane Street's market-making operations. Check the Jane Street filer page for the latest security identification.

How has Jane Street's AUM more than doubled in six quarters?

The growth from $309B to $662B reflects multiple factors: market appreciation (particularly in tech stocks), expansion of market-making activities into more instruments and geographies, and the increasing importance of ETF market-making as passive investing grows. Jane Street's proprietary trading profits, which are reinvested into operations, also contribute to balance sheet growth.

Is the 15.4% SPY concentration a risk?

In isolation, 15.4% in one instrument is elevated concentration. However, for a market-maker, this position is likely hedged through options, futures, and correlated instruments not reported on the 13F. The net directional exposure to SPY is almost certainly far smaller than the $95.9B gross position suggests. That said, a liquidity crisis in SPY — however unlikely — would create significant operational challenges.

Should retail investors follow Jane Street's stock picks?

No. Jane Street's 13F reflects the equity leg of an automated market-making and quantitative trading operation. The positions serve functions — hedging, arbitrage, liquidity provision — that have no equivalent in a retail portfolio. Replicating the top holdings without the associated hedges and derivatives would produce entirely different risk and return characteristics.

What to Watch

• SPY position trend: If the $95.9B position grows toward $100B+, it signals expanding market-making scale; a sharp decline could indicate reduced risk appetite
• Q1 2026 filing: Jane Street's prior Q1 filings show AUM drawdowns — will the pattern repeat from $662B?
• NVIDIA vs. Tesla positioning: At $37.9B and $36.2B respectively, any divergence in these two positions would signal shifting views on AI vs. EV
• Precious metals (GLD + SLV): The $27.2B combined position is notable — changes here may reflect macro hedging adjustments
• Position count trajectory: At 17,120, Jane Street already leads most filers. Further growth indicates expansion into new markets or instruments

Data sourced from Jane Street Group, LLC's Q4 2025 13F-HR filing with the SEC. Holdings represent a point-in-time snapshot as of December 31, 2025, and may not reflect current positions.