In case you missed it, there's a lot of buzz surrounding quantum computing these days. If you have any doubts, just check out the stocks of some up-and-coming quantum computing leaders. Shares of IonQ have soared nearly 6x over the last 12 months, and D-Wave Quantum stock is up roughly 1,400% during the same period.
Have the wealthiest investors noticed this trend? Almost certainly. In fact, billionaires are buying one quantum computing stock hand over fist, but it's not IonQ or D-Wave Quantum.
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Billionaires' big bets
While several smaller quantum computing companies are enjoying their time in the limelight, much larger companies have made significant progress in quantum computing. Google parent Alphabet (GOOG 1.47%) (GOOGL 1.46%) is one of them.
Alphabet's Google Quantum AI has already checked off two of the six major milestones on its quantum computing roadmap. In 2019, the unit claimed to have achieved quantum supremacy by solving a problem that would have taken a classical computer an enormously long time to handle. Four years later, Google Quantum AI demonstrated a logical qubit prototype that was a big step in quantum error correction.
Several billionaire investors really like Alphabet, especially Israel "Izzy" Englander. In the first quarter of 2025, Englander's Millennium Management hedge fund bought more than 2 million shares of Alphabet stock, increasing its stake by roughly 151%.
Ken Griffin loaded up on Alphabet stock in Q1, too. His Citadel Advisors hedge fund boosted its position in the Google parent by nearly 56%. Fellow billionaire David Tepper bought more than 128,000 additional Alphabet shares for his Appaloosa Holdings fund, ranking it Tepper's sixth-largest holding.
Quantum computing probably wasn't their top focus
Although billionaire investors have recently bought Alphabet stock hand over fist, quantum computing probably wasn't their top focus. Why did Englander, Griffin, and Tepper add to their positions in Alphabet?
During the first quarter, Alphabet's share price fell around 18%. My hunch is that billionaire hedge fund managers saw this sell-off as an attractive buying opportunity.
It wouldn't surprise me if they have bought even more shares of Alphabet in the second quarter as the company has the lowest valuation among the so-called "Magnificent Seven." Its shares trade at 19.3 times forward earnings.
The Google parent's price-to-earnings-to-growth (PEG) ratio, which is based on analysts' five-year earnings growth projections, is 1.38. No other Magnificent Seven stock has valuation metrics anywhere near those levels.
I also suspect that these deep-pocketed investors think Alphabet's growth prospects are strong. The company's Google Cloud unit is the fastest-growing of the major cloud service providers, and rising AI adoption should drive even greater demand for cloud services. Google Search and YouTube are still juggernauts, with no signs of their market dominance waning anytime soon. Alphabet's Waymo could have a huge opportunity as autonomous ride-hailing momentum accelerates.
Should you buy Alphabet stock, too?
Don't buy Alphabet stock just because Englander, Griffin, Tepper, or any other super-rich investor did. However, it's a good idea to consider their likely reasons for buying the stock.
Alphabet's valuation remains nearly as attractive today as it was at the end of the first quarter of 2025. The company's growth prospects should still be solid, as well. Don't overlook the risks that Alphabet faces, though.
The company has lost two major antitrust lawsuits over the last year. Although Alphabet is appealing, it could be forced to sell some of its businesses if the U.S. government prevails.
Google Search continues to face the potential for disruption by generative AI. Rumors have swirled about the possibility that Apple could acquire or partner with Perplexity, which has a popular AI search engine. Should Apple replace Google Search as its default search engine on its Safari browser, Google Search revenue could take a significant hit.
Overall, though, I think the pros for Alphabet (including the company's AI and quantum computing opportunities) outweigh the cons. Billionaire investors seem to have a similar view -- or at least they did earlier this year.
