Billionaire investor Stanley Druckenmiller 's top three biggest holdings at the end of June were all health-care stocks and he also invested back into one of his favorite artificial intelligence plays, Microsoft , according to a regulatory filing. The former lead portfolio manager for George Soros' Quantum Fund, who now runs his own Duquesne Family Office, hiked his stakes in Teva Pharmaceutical and biopharmaceutical company Insmed last quarter, making them his fund's second- and third-largest holdings, the filing showed. Clinical genetic testing company Natera remained Druckenmiller's top bet, worth more than half a billion at the end of June. The legendary investor, who has never had a down year in the markets, took a $100 million stake in Microsoft in the second quarter, after exiting the tech position in the third quarter of 2024. Druckenmiller was applauded for his big win on key AI player Nvidia in 2022 as he was one of the earliest investors to see the potential in the burgeoning industry, comparing the power of AI to the internet. He once called Nvidia and Microsoft his favored names to play the theme. However, he exited the winning bet last year, later admitting it was a "big mistake" as Jensen Huang's company continued its rally. Still, Microsoft is outperforming the market again this year, up 22% year to date. The stock topped a $4 trillion market cap on July 30 for the first time ever. Druckenmiller shot to fame after helping make a $10 billion bet against the British pound in 1992. He later oversaw $12 billion as president of Duquesne Capital Management before closing his firm in 2010.
