45% of Billionaire Bill Ackman's Portfolio Is Invested in 2 Trillion-Dollar Artificial Intelligence (AI) Stocks and a Company Whose Addressable Market Can 10X by 2033

Key Points

• Form 13Fs allow investors to see which stocks Wall Street's brightest asset managers are buying and selling.

• Billionaire Bill Ackman's largest holding is tackling an addressable opportunity expected to grow to more than $918 billion in eight years.

• Meanwhile, two members of the "Magnificent Seven" collectively account for almost a quarter of Pershing Square's invested assets.

• 10 stocks we like better than Uber Technologies ›

The amount of data available to investors can sometimes feel overwhelming. Between near-daily economic data releases and earnings season (the six-week period where most S&P 500 companies reveal their operating results), it can be easy to overlook something of importance.

For example, investors might have missed the filing of Form 13Fs with the Securities and Exchange Commission on Aug. 14. A 13F is a required quarterly filing by institutional investors with at least $100 million in assets under management (AUM) that provides investors with an under-the-hood look at which stocks Wall Street's brightest money managers have been buying and selling.

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Though billionaire Warren Buffett's trading activity is often the most-awaited by investors, he's not the only billionaire asset manager with a knack for spotting a good deal or delivering outsized returns. Activist investor Bill Ackman of Pershing Square Capital Management, who's overseeing $13.7 billion in AUM as of the midpoint of 2025, is another perfect example.

Activist investors tend to concentrate their assets and focus on businesses they believe can unlock shareholder value. Pershing Square's portfolio has just 11 holdings. Interestingly enough, a little over 45% of Ackman's invested assets are concentrated in three stocks:

• A company whose addressable market is projected to 10X over the next eight years; and
• Two trillion-dollar members of the "Magnificent Seven" that are leaning heavily on artificial intelligence (AI) as a core future growth driver.

Uber Technologies: 21% of invested assets

The largest holding in Ackman's portfolio, accounting for more than a fifth of Pershing Square's invested assets, is ride-share leader Uber Technologies (NYSE: UBER).

Based on estimates from Stratis Research, the global ride-sharing market is forecast to grow from an estimated $87.7 billion in 2025 to more than $918 billion by 2033. For those of you keeping score, this works out to a compound annual growth rate of 21% for the company leading the charge in ride sharing.

Domestically, Uber has been consistently dominant. Between September 2017 and March 2024, Uber's piece of the pie in the U.S. ride-share market has vacillated between 68% and 76%, based on data from AutoInsurance.com. It's the leader with brand recognition that Bill Ackman recognizes as having fantastic leadership. Uber has been able to shift a once-unprofitable business into a cash-generating machine.

Additionally, Uber Technologies has the luxury of being more than just a ride-sharing company. It operates the Uber Eats delivery platform, as well as freight logistics. The nonlinear nature of economic cycles, which sees the U.S. economy expand for considerably longer than it contracts, should help Uber's ancillary operations flourish over time.

Perhaps the one knock against Uber is the company's valuation. Although Ackman has stated that Uber stock can be "purchased at a massive discount to its intrinsic value," its price-to-sales (P/S) ratio of 4.1 implies its rivals might be a better deal. Uber will need to add to its global market share if it's going to sustain a premium P/S ratio over its peers.

Image source: Getty Images.

Alphabet: 15.1% of invested assets (including both share classes)

Billionaire Bill Ackman is also wagering big on the future of artificial intelligence. As of the end of June, he had more than 15% of his fund's assets invested in Alphabet (NASDAQ: GOOG)(NASDAQ: GOOGL), with 8.2% held in the Class C shares (GOOG) and 6.9% derived from the Class A shares (GOOGL).

Though Alphabet is absolutely counting on AI as a growth driver, it's worth recognizing that its primary revenue driver is advertising. Alphabet's Google search engine has accounted for between 89% and 93% of worldwide internet search share dating back more than a decade. This level of dominance has afforded Google exceptional ad-pricing power, and it ensures that Alphabet is able to take full advantage of disproportionately long periods of economic expansion.

Alphabet's Ai ambitions primarily concern the application of AI solutions within Google Cloud, the world's No. 3 cloud infrastructure service platform. Google Cloud generates considerably higher margins for Alphabet than ads, and it's growing a lot faster. Sales were up 32% in the June-ended quarter from the prior-year period, with an annual revenue run-rate of more than $54 billion.

Alphabet is incorporating generative AI solutions into Google Cloud, as well as giving clients the ability to build and train large language models. These actions can maintain or reaccelerate Google Cloud's already stellar growth rate.

Furthermore, Ackman's largest AI holding is the cheapest member of the Magnificent Seven. Shares of Alphabet can be scooped up, as of this writing on Sept. 5, for 22 times forward-year earnings, which is reasonable for a company with a sustained low-double-digit growth rate and phenomenal operating cash flow.

Amazon: 9.3% of invested assets

The other trillion-dollar AI stock that combines with Alphabet and Uber Technologies to account for 45% of billionaire Bill Ackman's $13.7 billion in AUM is e-commerce juggernaut Amazon (NASDAQ: AMZN).

While most people familiarize themselves with Amazon through its world-leading online marketplace, this premier revenue producer generates low margins and (comparatively) minimal operating cash flow. The bulk of Amazon's operating income comes from its ancillary segments, headlined by Amazon Web Services (AWS).

AWS is the global leader in cloud infrastructure service spend. Based on estimates from tech analysis firm Canalys, AWS accounted for 32% of worldwide spend during the first quarter, which is more than three times as much as Google Cloud. AWS is aggressively leaning on generative AI and large language model capabilities to allow its subscribers to grow and enhance their businesses. The annual sales run-rate for AWS has surpassed $123 billion, as of the June-ended quarter.

But AWS isn't the only operating segment maintaining a double-digit growth rate for Amazon. Subscription services have sustained low-teens growth on the heels of exclusive content wins from the National Football League and National Basketball Association. Meanwhile, billions of monthly visitors have translated into consistent year-over-year advertising services growth of around 20%.

Though Amazon stock isn't cheap according to the traditional price-to-earnings (P/E) ratio, its multiple relative to its forward-year cash flow is historically inexpensive. After commanding a year-end cash flow multiple of 23 to 37 throughout the 2010s, shares of Amazon can be purchased for 12.6 times consensus cash flow per share in 2026. This is probably what has billionaire Bill Ackman's full attention.

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Sean Williams has positions in Alphabet and Amazon. The Motley Fool has positions in and recommends Alphabet, Amazon, and Uber Technologies. The Motley Fool has a disclosure policy.