Billionaire Stanley Druckenmiller Sold His Entire Stake in Palantir and Has, Once Again, Started Loading Up on This Trillion-Dollar Artificial Intelligence (AI) Stock

Key Points

• Form 13F filings offer investors a way to track which stocks Wall Street's savviest money managers are buying and selling.

• Billionaire Stanley Druckenmiller exited his fund's entire stake in Palantir over a nine-month stretch -- and profit-taking might explain only part of the story.

• Meanwhile, Druckenmiller welcomed a familiar face, which is an undisputed leader in the artificial intelligence (AI)-data center space, with open arms.

• 10 stocks we like better than Broadcom ›

For many investors, earnings season is the highlight of each quarter. This is the six-week period where the lion's share of S&P 500 companies reports their operating results from the previous three-month period.

However, a strong argument can be made that Form 13F filings can be just as informative. A 13F is a required filing by institutional investors with at least $100 million in assets under management no later than 45 calendar days following the end to a quarter. It provides a concise rundown of which stocks Wall Street's savviest investors were buying and selling in the latest quarter.

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Although Warren Buffett is traditionally the most followed of all asset managers, he's not the only billionaire investor with a penchant for outsized returns. Duquesne Family Office's billionaire boss Stanley Druckenmiller is another fund manager with a knack for spotting good deals.

Over the trailing year (ended June 30, 2025), Duquesne's 13Fs show Druckenmiller completely exited his fund's stake in one of the hottest and highest-flying artificial intelligence (AI) stocks, Palantir Technologies (NASDAQ: PLTR), and looks to be, once again, building a position in a critical trillion-dollar AI stock.

Palantir's heave-ho may have to do with more than just profit-taking

When the midpoint of 2024 came to a close, Duquesne Family Office was holding nearly 770,000 shares of AI-data mining specialist Palantir.

It's been a popular stock to own thanks to the irreplaceability of its AI- and machine learning-propelled Gotham and Foundry platforms. Gotham tends to land multiyear contracts with the U.S. and other federal governments to help with military mission planning and data collection. As for Foundry, it's used by businesses to make sense of their data and improve their operating efficiency. With no clear-cut replacement for the software-as-a-service solutions Palantir provides, it's earned quite the premium from investors.

But between June 30, 2024, and March 31, 2025, Druckenmiller jettisoned his fund's entire stake.

Profit-taking is the most logical of all explanations as to why Palantir stock was given the heave-ho. The 69 securities in Duquesne Family Office's investment portfolio, as of June 30, 2025, have been held for an average of less than seven months. In other words, its billionaire boss isn't shy about cashing in his chips following a sizable gain, as was the case with Palantir Technologies.

The worry is that profit-taking might not be the only reason Stanley Druckenmiller showed shares of Palantir to the door.

The most glaring potential problem with Palantir stock is its valuation. Although "value" is subjective, and Palantir is deserving of some level of premium because of its irreplaceability, the company's price-to-sales (P/S) ratio is so far above historical norms that it's left the chat.

Over multiple decades, companies on the leading edge of a next-big-thing investment trend have seen their shares peak at roughly 30 to 40 times sales. Palantir entered this week with a P/S ratio of 115. Even with the company consistently surpassing Wall Street's sales and profit projections, there's nothing it can report from an operating standpoint that justifies a triple-digit P/S ratio, let alone a P/S ratio of 30 to 40, which is a level no other megacap company has been able to sustain.

Additionally, insiders can't seem to get rid of their shares fast enough. Since becoming a publicly traded company in late September 2020, only one insider purchase has been made by a current/former executive or director, compared to more than $7.6 billion in net stock sold. If insiders won't purchase Palantir stock, why should billionaires or everyday investors?

Image source: Getty Images.

This trillion-dollar AI networking stock was back on Druckenmiller's menu

At the other end of the spectrum, Duquesne's billionaire chief oversaw quite a bit of buying. While most of this buying activity had nothing to do with AI stocks, one pivotal, trillion-dollar company within the AI space does stand out: Broadcom (NASDAQ: AVGO).

Broadcom isn't a stranger to Stanley Druckenmiller's fund. During the third quarter of 2024, he oversaw the purchase of almost 240,000 shares of this AI networking giant. But in the subsequent quarter, this position was completely exited.

Based on Duquesne's second-quarter 13F, Broadcom is back. During the June-ended quarter, Druckenmiller purchased a little over 86,000 shares, worth close to $24 million, as of the midpoint of 2025.

Wall Street's mini-crash in early April is probably one of the reasons Druckenmiller loaded up on shares of Broadcom, once again. Following President Donald Trump's unveiling of its tariff and trade policy on April 2, the benchmark S&P 500 endured its fifth-largest two-day percentage decline in 75 years. A nearly one-week period of fear and pessimism created a unique opportunity for investors like Druckenmiller to snag amazing businesses at a discount. Although we don't know if this is when Duquesne added to Broadcom, the early portion of April would make sense.

Broadcom's hardware is integral to the success of the AI revolution. Its solutions are connecting tens of thousands of graphics processing units in enterprise data centers to maximize their compute capacity, as well as reduce tail latency. The latter is particularly important, as minimizing lag is a necessity for AI-empowered software and systems making split-second decisions.

Broadcom's custom AI application-specific integrated circuits (ASICs) are also a massive opportunity. CEO Hock Tan believes custom ASICs could help drive $60 billion to $90 billion in revenue to Broadcom from three of its largest hyperscaler customers by 2027.

Another key aspect to Broadcom's success is its growth potential outside of artificial intelligence. While there's no denying that AI networking solutions account for the bulk of its growth at the moment, Broadcom generates quite a bit of sales from wireless chips and solutions for smartphones, enterprise cybersecurity, and various solutions used in industrial robotics and automobiles. If an AI bubble were to form and burst, Broadcom would have other operating segments to fall back on.

The final catalyst for billionaire Stanley Druckenmiller might be Broadcom's valuation. If Duquesne's boss lapped up shares in early April, he'd have nabbed Broadcom at a forward price-to-earnings ratio of less than 20, which is a solid value for a company slated to grow its sales by more than 20% annually.

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Sean Williams has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Palantir Technologies. The Motley Fool recommends Broadcom. The Motley Fool has a disclosure policy.