It’s 13F season, which means we finally get a peek at what some of Wall Street’s biggest investors were doing while we watched the market whip around. That said, few filings are more fun to open than the one from the firm Jim Simons built.
Simons was a mathematician and former Cold War codebreaker who became a trailblazer in the hedge fund industry.
At Renaissance Technologies, he hired scientists and used computers to spot patterns in market data. He died in May 2024 at age 86, with a net worth of more than $31 billion, but his track record still turns heads.
Renaissance’s Medallion Fund averaged nearly 39% per year after fees from 1988 through 2018, as reported by MarketWatch. Warren Buffett’s Berkshire Hathaway compounded at 20.5% over a longer stretch ending that same year.
Now, Renaissance’s Nov. 12 filing shows the firm has all but walked away from Nvidia (NVDA) in Q3. Two other tech stakes were worth a combined $2.24 billion at quarter-end.
Renaissance cut its Nvidia stake by 99.7% before Huang resigned
Renaissance Technologies went from holding 7.09 million Nvidia shares at the end of June to just 23,170 at the end of September.
That’s a massive reduction of 7 million shares, or 99.7% (a near-exit), which meant that a position worth $1.42 billion at the previous quarter’s close was down to $5.3 million, WhaleWisdom noted.
The interesting twist is that Renaissance had just been rebuilding its position of late. It held 7.42 million shares in June 2025, dropped to about 871,000 by December, then climbed to 2.53 million in March 2026 before nearly tripling that stake by June.
Given the fluctuations in exposure, the move wasn’t that sudden.
“We make our forecast. Then, shortly thereafter, we reevaluate the situation and revise our forecast, and our portfolio,” Simons told the Greenwich Roundtable, as reported by Institutional Investor in 2000.
That’s a pretty useful way to read the swings.
A data-driven manager can consider resizing a position without making a long-term call on the company. Interestingly, Nvidia announced Jensen Huang’s resignation and named CFO Colette Kress interim CEO on Nov. 12, the day the filing went public.
By then, the quarter-end snapshot was already six weeks old, so clearly the cut wasn’t a response to the announcement.
Interestingly, Renaissance boosted its stake in Nvidia rival Advanced Micro Devices (AMD) by over 140%. It added $695 million worth of shares, bringing the total AMD stake to $1.2 billion.
Jim Simons’ firm reported $2.24 billion in Micron and SpaceX shares at quarter-end.
The $2.24 billion reveal in Micron and SpaceX
Renaissance more than septupled its Micron Technology (MU) stake, from 211,580 shares in June to 1.52 million in September, worth $1.62 billion, WhaleWisdom confirmed.
It also disclosed 4.11 million SpaceX (SPCX) shares worth $620.5 million, a position absent from its June filing, even though SpaceX had already gone public. Collectively, the holdings represented about 3% of the firm’s reported 13F portfolio and were worth $2.24 billion on Sept. 30.
More Nvidia:
- Microsoft just gave Nvidia shareholders a reason to pay attention
- Nvidia has a stake in SpaceX that came from an unexpected place
- Nvidia’s $12.9 billion deal could shape the AI apps you use
Micron remains one of 2026’s standout chip stocks, up 180% for the year through Nov. 12.
AI accelerators require a ton of high-bandwidth memory to continue keeping data moving, and demand for memory and storage helped drive a surge in sales. Micron’s fiscal Q4 sales jumped to $54.2 billion, nearly five times the prior-year figure. Much of the outsized results are due to a demand/supply imbalance.
Moreover, SpaceX is no longer just a bet on rockets. Its Q3 sales rose 161% to $14.6 billion, with most of the increase coming from its AI business and Starlink connectivity, not launches.
That’s what makes the two holdings interesting together.
Micron sells memory into the AI buildout; SpaceX is spending to build its own computing capacity. Different businesses, but not entirely different risks.
What to watch before following Renaissance’s trades
When the next batch of 13Fs lands, it’s important to look at share counts first and dollar values second. A position can get bigger on paper simply because the stock rallied.
Then it’s worthwhile to look back at least four quarters.
A manager that adds steadily is doing something different from one that repeatedly builds and cuts the same stake, as Renaissance did with Nvidia. Compare filings from managers with similar strategies and then potentially call it a trend.
For Nvidia, the more useful signal comes on Nov. 17.
Nvidia investors will be looking at whether Kress’s earnings commentary points to any change in customer demand or product delivery timelines.
For Micron, watch memory pricing and gross margins as supply expands.
For SpaceX, compare Starlink and AI revenue growth with the cash the company is spending on data centers and launch infrastructure.
Related: 5-star analyst revamps Nvidia stock target as CEO departs
