Jane Street opened 93 new positions in Q4 2025 while leaving their SPY and NVIDIA core completely intact. The market-making giant expanded at the periphery without disturbing the trading engine at the center.
The filing detail
| Metric | Value |
|---|---|
| New positions | 93 |
| Core unchanged | SPY (~15%), NVDA, TSLA stable |
| Total AUM | $662B |
| Total positions | 17,120 |
What 93 new positions means for a market maker
At a traditional asset manager, 93 new positions = 93 new research-driven investment theses. At Jane Street, 93 new positions likely means:
1. New options underlyings
As new stocks become optionable or existing options markets expand, Jane Street adds stock positions to delta-hedge. 93 new names = 93 stocks where options activity increased enough to require inventory.
2. ETF component changes
When indices reconstitute (adding/removing stocks), ETF market makers need inventory in the new components. Index additions create automatic new positions.
3. IPO and new listing activity
Newly public companies that develop sufficient trading volume get added to Jane Street's market-making universe.
4. Client demand expansion
Institutional clients requesting liquidity in new names = Jane Street building inventory to facilitate those trades.
The stable core: SPY + NVIDIA
While 93 new positions entered, the SPY-NVIDIA core didn't change:
| Core position | Q3 → Q4 | Signal |
|---|---|---|
| SPY (~15%) | Stable | ETF market-making demand unchanged |
| NVIDIA | Stable | Options hedging demand unchanged |
| TSLA | Stable | Options hedging demand unchanged |
The stability of the core tells you that the biggest market-making flows (SPY trading, NVDA options, TSLA options) didn't shift. The 93 new positions are at the margin — expanding the universe, not restructuring it.
Core-periphery pattern across filers
This same core-periphery pattern appears at multiple major filers:
| Filer | Stable core | Active periphery | What it means |
|---|---|---|---|
| Jane Street | SPY/NVDA/TSLA | +93 new | Market-making universe expanding |
| Capital World | AVGO at #1 | 41 turnover | Research engine active at edges |
| Bridgewater | IVV core | 290 new/281 exits | Macro repositioning |
| Goldman | SPY/TSLA | 51 new | Trading desk + WM additions |
The pattern is universal at scale: the core positions (biggest, most liquid, most structurally important) stay stable. Activity happens at the edges.
Originally published at 13F Insight
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