Dan Loeb is known as a mover and a shaker in the investing world. He founded the New York-based hedge fund Third Point in 1995. It now has roughly $11.5 billion in assets under management. Loeb's net worth stands at $3.3 billion, according to Forbes.

The activist investor did some moving and shaking in his hedge fund's portfolio in the fourth quarter of 2023. Loeb reduced his stakes in Amazon (AMZN 0.75%) and Microsoft (MSFT -1.00%). However, the billionaire investor bought another "Magnificent Seven" stock.

Taking profits

Loeb sold 210,000 shares of Microsoft in Q4. While this reduced Third Point's stake in the tech giant by over 9.4%, Microsoft remains the second-largest holding in the hedge fund's portfolio.

The billionaire investor has owned Microsoft off and on since 2006. He most recently initiated a new position in the fourth quarter of 2022, just in time to ride the generative AI wave started by OpenAI's launch of ChatGPT. Microsoft was a major beneficiary of this wave thanks to its partnership with OpenAI.

Third Point first owned Amazon in late 2019 and held the stock through the second quarter of 2022. Loeb didn't stay on the sidelines long with the e-commerce and cloud services leader. He initiated a new position in Amazon in the second quarter of 2023. Although he reduced Third Point's stake in the stock by nearly 10.3% in Q4 2023, Amazon still ranks as the hedge fund's third-largest holding.

Why did Loeb trim his positions in Amazon and Microsoft? The most likely reason is he wanted to take some profits. Both stocks delivered impressive gains last year.

A bigger bet on Meta

Although Loeb cooled somewhat on two Magnificent Seven stocks, he placed a bigger bet on Meta Platforms (META -2.41%). The hedge fund manager increased Third Point's stake in Meta by nearly 5.5% in Q4 2023. The $410.6 million value of the position made Meta the sixth-largest holding for Third Point at the end of 2023.

Loeb's history with Meta goes back to the second quarter of 2016 when he first bought the stock. He owned shares of the social media company for a little over two years before exiting the position. The activist investor again bought Meta stock in the second quarter of 2020 and maintained a position through 2021 Q4. Loeb went back to the well in the third quarter of 2023 with another new stake in Meta.

Like Amazon and Microsoft, Meta enjoyed a generative AI tailwind last year. However, I suspect that wasn't Loeb's primary reason for adding to his position in the stock. Instead, my hunch is that Loeb liked Meta's moves to increase its profitability.

Those efforts are paying off. Meta's earnings more than tripled year over year in 2023 Q4. Full-year profits jumped 69%.

Did Loeb make the right moves?

In one sense, Loeb went one for three with these Magnificent Seven transactions. Loeb's decision to increase Third Point's stake in Meta is already paying off. Meta stock has skyrocketed over 45% since the end of 2023. However, Amazon and Microsoft are also up by double-digit percentages year to date. Loeb could have made more money by holding his shares in both companies.

However, trimming the positions in Amazon and Microsoft could still have been the right call for Loeb. Both stocks make up significant percentages of Third Point's portfolio. You can't blame any investor for wanting to ensure their holdings aren't overly concentrated in a handful of stocks.

Over the long term, I think that Loeb -- and other investors -- will be well served by owning all three of these stocks. Amazon's and Microsoft's cloud businesses should continue to grow robustly thanks largely to AI. I like Meta's focus on business messaging and smart glasses with embedded AI assistants. I predict Amazon, Microsoft, and Meta will remain magnificent for a long time to come.