Leopold Aschenbrenner's hedge fund purchased call options with premiums totaling hundreds of millions of dollars between late last week and Sept. 11. The positions focus on artificial intelligence and semiconductor companies, specifically AMD, SK Hynix, CoreWeave, Bloom Energy, and SanDisk, based on reporting from CNBC.

Reporter David Faber characterized the buying at the Situational Awareness fund as being of "some significance" for the market. These trades signal a return to the AI sector for Aschenbrenner after his previous fund collapsed earlier this year.