Alphabet's Largest Investment Holding -- Up 2,800% in 2 Years -- Is One of the Hottest Stocks Among Institutional Investors

You might not realize it, but one of the most important data releases of the entire quarter occurred on Feb. 17: the deadline for institutional investors with at least $100 million in assets under management (AUM) to file Form 13F with regulators.

A 13F filing intricately details which stocks Wall Street's prominent money managers bought and sold in the latest quarter -- but it's not relegated just to billionaires. Companies overseeing more than $100 million in AUM are also required to file a 13F. This includes artificial intelligence (AI) juggernaut Alphabet (NASDAQ: GOOGL)(NASDAQ: GOOG), whose largest investment holding, satellite-based cellular broadband services provider AST SpaceMobile (NASDAQ: ASTS), has been one of the most-coveted stocks by institutional investors.

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Google parent Alphabet is betting big on this space stock

Although Alphabet's $3.7 trillion market cap is almost entirely derived from its virtual internet search monopoly with Google and its long-term AI ambitions via Google Cloud, its fourth-quarter 13F shows that 25% of its nearly $2.6 billion investment portfolio can be traced to its top holding, AST SpaceMobile.

Shares of AST have more than tripled over the last year, which is when Alphabet initially purchased 8,943,486 shares of the company. But over the trailing two-year period, AST SpaceMobile stock has rallied more than 2,800%!

It's an especially popular stock to own among institutional investors. According to WhaleWisdom.com, 127 more 13F filers were holding AST shares at the end of December, compared to Sept. 30, 2025.

The excitement investors have shown toward AST SpaceMobile and its outsize returns boils down to two factors.

First, AST's BlueBird satellites are designed to work with existing smartphone technology. Whereas other companies have previously attempted to launch global cellular broadband networks that required specialized phones, AST's satellites work with existing equipment.

Second, and arguably most important, AST SpaceMobile has partnered with over 50 global mobile network providers currently serving "nearly 6 billion subscribers combined," per the company. Instead of competing against established telecom companies, it's allied with them and given itself a clear path to parabolic sales growth as its satellite network takes shape.

Image source: Getty Images.

AST SpaceMobile: An intriguing story stock that may be priced for perfection

With full-year sales projected to explode from an estimated $59 million in 2025 (prior to reporting its fourth-quarter operating results) to nearly $3.1 billion in 2029, AST SpaceMobile would appear unstoppable. However, even Wall Street's hottest stocks face challenges.

For instance, AST's success is dependent on the timely launch of its satellites, as well as ongoing innovation, allowing for more data to be handled by next-generation satellites. In December, a less than one-week delay in the launch of a BlueBird 6 satellite caused a double-digit percentage drop in AST SpaceMobile's stock.

AST's operating model also runs the risk of being disrupted by inflation and supply chain issues. The estimated cost to produce its satellites has been climbing, prompting the company to price $1 billion in convertible senior notes last month. Convertible debt can lead to share-based dilution and is a firm reminder that ongoing cash burn is the norm (for now) for AST.

A price-to-sales multiple of more than 10 times forecast 2029 revenue suggests that AST SpaceMobile, while popular among 13F filers such as Alphabet, may be priced for perfection.

Sean Williams has positions in Alphabet. The Motley Fool has positions in and recommends AST SpaceMobile and Alphabet. The Motley Fool has a disclosure policy.