Eli Lilly reported total tirzepatide sales that rocketed 272% year over year to $11 billion during the first nine months of 2024. Billionaire investors like Griffin are piling into Viking Therapeutics because it's developing a dual GLP-1/GIP receptor agonist, tentatively named VK2735, that could become even more successful than tirzepatide.

Interestingly, while Nvidia (NASDAQ: NVDA) and Taiwan Semiconductor (NYSE: TSM) are both positioned to benefit from demand for artificial intelligence (AI) infrastructure, Griffin bought one stock and sold the other in the third quarter.

Ken Griffin is arguably one of the most successful investors of all time. He made a name for himself when he shorted stocks just ahead of the 1987 market crash that came to be known as "Black Monday." His profits last year topped $7 billion as his returns of roughly 15% outpaced many of his peers.