When Leopold Aschenbrenner published a sprawling manifesto last year warning about the breakneck race toward artificial superintelligence, he quickly became one of Silicon Valley’s most closely watched voices on AI. Now the former OpenAI researcher is drawing attention on Wall Street, too. Shares of Nebius Group surged Thursday after Aschenbrenner’s hedge fund, Situational Awareness, disclosed a major stake in the Dutch cloud computing provider, giving investors a fresh glimpse into how one of the AI industry’s emerging thinkers is betting on the sector’s future. Born in Germany, Aschenbrenner was for a short time a researcher at OpenAI before leaving the AI researcher. Aschenbrenner first gained attention last year after releasing a widely circulated 165-page essay on AI . He has since shifted into investing, launching a hedge fund despite having no prior professional money management background. His San Francisco-based Situational Awareness had about $4 billion in reported investments at the end of March. Aschenbrenner, who’s in his 20s, has characterized the firm as an AI-focused “brain trust.” The fund has drawn support from several prominent technology and investment figures, including Patrick and John Collison of Stripe, along with Daniel Gross and Nat Friedman, both of whom were recently tapped by Mark Zuckerberg to assist with Meta ‘s AI initiatives. The fund invests in publicly traded companies expected to benefit from AI adoption — including semiconductor, infrastructure and power firms — while also backing startups such as Anthropic. Aschenbrenner has told investors the strategy also includes smaller short positions against industries that may struggle to adapt to AI disruption. Situational Awareness reported owning 12.4 million Class A shares of Nebius, according to a regulatory filing published Wednesday, representing a 5.6% stake in the company. Nebius became the firm’s largest equity holding. Some of its other, large positions include CoreWeave and Bloom Energy — companies tied to the infrastructure demands required to power advanced AI models. But the fund is also hedging aggressively against parts of the trade becoming overheated. Situational Awareness disclosed sizable put-option positions linked to Nvidia , Broadcom , Advanced Micro Devices and Oracle , along with a bearish wager against the VanEck Semiconductor ETF . Still, the 13F filing represents only a snapshot of the fund’s holdings at the end of March. Apart from the newly disclosed Nebius stake, Aschenbrenner may have already reduced or exited some of the put-option positions as AI-linked stocks continued to swing sharply in recent months.