For a lot of investors, earnings season is the highlight of every quarter. It's the roughly six-week period where most S&P 500 components report their operating results and give investors an inside look at how "healthy" corporate America really is.

But earnings season is far from the only important event each quarter for investors. The filing of Form 13Fs with the Securities and Exchange Commission can be equally valuable.

A 13F provides a concise snapshot of which stocks, exchange-traded funds (ETFs), and options Wall Street's savviest money managers purchased and sold in the latest quarter. It's a required filing for institutional investors with at least $100 million in assets under management no later than 45 days following the end to a quarter.

A stock chart displayed on a computer monitor that's reflecting on the eyeglasses of a money manager.

Image source: Getty Images.

While Warren Buffett is the most-prominent of all money managers, he's not the only billionaire with an impressive investing track record. Duquesne Family Office's billionaire boss Stanley Druckenmiller knows a thing or two about spotting amazing deals hiding in plain sight.

Over the last four 13Fs (July 1, 2024 – June 30, 2025), Druckenmiller has opened 45 new positions, added to 11 existing holdings, pared down Duquesne's stakes in 13 stocks, and has seen 40 securities leave the portfolio in their entirety. Among these dozens of trades, four stand out.

In particular, Druckenmiller sent his fund's entire stakes in Wall Street's hottest artificial intelligence (AI) stocks packing, Nvidia (NVDA -0.77%) and Palantir Technologies (PLTR -7.29%). At the same time, he's been building up a position in two phenomenal stocks for four consecutive quarters.

Shares of AI superstars Nvidia and Palantir were sent to the chopping block

Few companies have dazzled Wall Street and investors since 2023 began quite like Nvidia and Palantir. Shares of Nvidia have catapulted close to 1,200%, with the company now just $400 billion away from becoming the first $5 trillion business. As for Palantir, it's rocketed higher by more than 2,800% over the same time frame and is the 20th-biggest public company traded on U.S. exchanges.

These truly jaw-dropping gains reflect the competitive advantages and sustainable moats both companies enjoy. Nvidia is the premier supplier of AI-graphics processing units (GPUs) deployed in enterprise data centers. No external GPU providers have come close to matching the compute abilities of Nvidia's Hopper (H100), Blackwell, and Blackwell Ultra chips.

As for Palantir, neither of its AI- and machine learning-driven software-as-a-service platforms are replaceable at scale. Gotham helps federal governments plan and supervise military missions and typically secures multiyear contracts from the U.S. government and its allies. The other operating platform, Foundry, is a subscription-based service that assists businesses with understanding their data and streamlining their operations.

With Nvidia and Palantir not having to look over their proverbial shoulders, both have thrived.

Nevertheless, this hasn't stopped Stanley Druckenmiller from sending both to the chopping block. Duquesne's billionaire chief disposed of all 214,060 shares of Nvidia during the third quarter of 2024, and sent nearly 770,000 shares of Palantir packing over a nine-month stretch from June 30, 2024 to March 31, 2025.

Simple profit-taking is one possible reason for this selling activity. With both stocks rapidly climbing amid the AI revolution, and Druckenmiller being a relatively active trader, cashing in his chips when the opportunity presents itself is common. But there may be more to this selling than initially meets the eye.

During a May 2024 interview with CNBC, Druckenmiller stated that, "AI might be a little overhyped now, but under-hyped long term." This speaks to the idea that every game-changing technological innovation for more than three decades has endured a bubble-bursting event early in its expansion. With most businesses not yet optimizing their AI solutions nor generating a positive return on their AI investments, a bubble event would be big-time trouble for Nvidia and Palantir.

The other potential issue for Druckenmiller is the respective valuations of Nvidia and Palantir. Historically, megacap companies on the leading edge of game-changing trends have topped out at price-to-sales (P/S) ratios of 30 to 40, give or take a little bit in each direction. Nvidia has a P/S ratio that's, once again, approaching 30. Meanwhile, Palantir's P/S ratio is a mind-blowing 137! Neither figure has ever been supported by a megacap company for an extended period.

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Image source: Getty Images.

Billionaire Stanley Druckenmiller has piled into TSMC and Teva for four consecutive quarters

At the other end of the spectrum, we find two stocks that Duquesne Family Office's boss simply can't get enough of: world-leading chip fabrication company Taiwan Semiconductor Manufacturing (TSM 1.50%), which is commonly known as TSMC, and drug developer Teva Pharmaceutical Industries (TEVA -0.22%). Both stocks have been purchased by Druckenmiller for four straight quarters.

TSMC has quickly become Duquesne's fifth-largest holding:

  • Q3 2024: 57,355 shares purchased
  • Q4 2024: 50,160 shares purchased
  • Q1 2025: 491,265 shares purchased
  • Q2 2025: 166,305 shares purchased (765,085 total shares held)

There's no question that the evolution of AI is TSMC's biggest catalyst and attraction. Nvidia and other external GPU providers are turning to Taiwan Semiconductor to produce the chips that fuel split-second decision-making in AI-accelerated data centers. TSMC is expanding its chip-on-wafer-on-substrate capacity at a breakneck pace and still can't keep up with seemingly insatiable hardware demand.

But what's great about TSMC is that it's much more than just an AI stock. This relatively new member of the trillion-dollar club also provides chips used in next-generation smartphones, Internet of Things devices, and even automobiles, which are becoming more tech-dependent with each passing year. If an AI bubble were to form and burst, TSMC would seemingly be in better shape than Nvidia to weather the storm.

The other apple of Druckenmiller's eye is brand-name and generic-drug developer Teva Pharmaceutical, which has vaulted to Duquesne's No. 2 holding by market value:

  • Q3 2024: 1,427,950 shares purchased
  • Q4 2024: 7,569,450 shares purchased
  • Q1 2025: 5,882,350 shares purchased
  • Q2 2025: 1,089,185 shares purchased (15,968,935 total shares held)

Teva had been held down for the better part of a decade by a slew of issues, ranging from litigation concerning its role in the opioid crisis to the loss of sales exclusivity for former blockbuster multiple sclerosis drug Copaxone. Teva also (in hindsight) grossly overpaid for generic-drug company Actavis, which ballooned its outstanding debt.

The good news is Teva has decisively addressed all of its issues. Management has overseen the sale of non-core assets and used cash flow from operations to meaningfully reduce its net debt. It has better financial flexibility than it's had over the last decade.

CEO Richard Francis has also overseen an operating shift that places more emphasis on novel-drug development. Even though brand-name drugs have finite periods of sales exclusivity, their growth potential and margins are far superior to generic therapies. Tardive dyskinesia drug Austedo is on track to meet or surpass $2 billion in sales this year and has been Teva's star performer the last few years.

Perhaps most importantly, Teva firmly placed its litigation concerns in the rearview mirror. In early 2023, it agreed on a $4.25 billion opioid settlement with 48 states to be spread across 13 years that includes up to $1.2 billion worth of generic Narcan (the opioid overdose reversal drug) delivered to states. With this settlement quantified, it now allows Teva's microscopic forward price-to-earnings ratio to expand.