Former OpenAI Researcher's Fund Buys Stake in AI Firm Nebius, Stock Surges
Nebius Group, a Dutch AI infrastructure provider spun out from Yandex, saw its stock surge over 10% on May 28, 2026, after Situational Awareness, a hedge fund founded by former OpenAI researcher Leopold Aschenbrenner, disclosed a 5.6% stake worth nearly $2.6 billion. The company, which provides GPUs for AI training and has partnerships with Meta and Nvidia, has risen 149% year-to-date. The investment signals strong confidence in Nebius as a key European AI compute player.
Cross-source coverage
Wire timeline
Nebius Stock Surges on AI Investor Leopold Aschenbrenner's Stake Disclosure
Nebius Group (NASDAQ: NBIS) shares jumped nearly 12% on May 28, 2026, after it was revealed that Leopold Aschenbrenner's multi-billion-dollar AI hedge fund, Situational Awareness, holds a 5.6% stake (over 12.4 million shares). The cloud infrastructure provider has seen its stock rise about 470% over the past year, riding the AI wave. The company recently raised its guidance for data center power capacity under contract and announced a partnership with Bloom Energy to deploy fuel cell systems. Despite the rally, analysts caution that Nebius's market cap has reached nearly $60 billion, and any setbacks to its growth plan could hit shares hard. The Motley Fool's Stock Advisor did not include Nebius in its list of 10 best stocks to buy now.
Yahoo FinanceAI data center Nebius pops 8.5% as Situational Awareness adds stake
Nebius (NASDAQ: NBIS), an AI infrastructure company classified as a 'neocloud,' saw its shares rise 8.58% to $225 in morning U.S. trading after disclosing a 5.6% ownership stake from Situational Awareness, a hedge fund focused on AI/HPC, powered land, and energy firms. The fund, founded by former OpenAI member Leopold Aschenbrenner in 2024, operates on a thesis of exponential AI growth benefiting powered land companies. Nebius, which builds and maintains AI infrastructure through vertical ownership of land, power, and compute, is up 169% year-to-date and recently reported a strong Q1 2026 revenue beat. Situational Awareness also holds positions in former Bitcoin mining firms such as Keel Infra, Riot Platforms, Bitdeer, and IREN, while trimming Core Scientific and maintaining a long position in Intel.
Yahoo FinanceAI data center Nebius pops 8.5% as Situational Awareness adds stake
Shares of Nebius (NASDAQ: NBIS), an AI infrastructure company focused on building and maintaining data centers through vertical ownership of land, power, and compute, rose 8.58% to $225 in morning U.S. trading after disclosing a 5.6% ownership stake from hedge fund Situational Awareness. The fund, founded in 2024 by former OpenAI member Leopold Aschenbrenner, focuses on AI/HPC, powered land, and energy firms. Nebius, classified as a 'neocloud,' is up 169% year-to-date and recently reported a large revenue beat for Q1 2026. Situational Awareness also holds positions in former Bitcoin mining firms including Keel Infra, Riot Platforms, Bitdeer, and IREN, while trimming Core Scientific and maintaining a long position in Intel.
Yahoo FinanceNebius Shares Jump Over 10% After Former OpenAI Employee's Fund Buys Stake
AI infrastructure firm Nebius Group's shares surged more than 10% in premarket trading on May 28, 2026, after Situational Awareness, a fund managed by former OpenAI employee Leopold Aschenbrenner, became its largest shareholder. The fund disclosed a 5.6% stake in Nebius, valued at nearly $2.6 billion. Situational Awareness, which managed $13.67 billion as of March 31, has grown 148% since the end of 2025. Aschenbrenner previously worked on OpenAI's 'Superalignment' team, which has since been disbanded. The investment signals confidence in Nebius as a key player in the AI infrastructure race, following the company's report of an almost eightfold increase in quarterly revenue earlier this month.
Yahoo FinanceNebius Stock Surges After Ex-OpenAI Employee's Fund Discloses Stake
Dutch cloud provider Nebius saw its stock surge 11% in premarket trading after Situational Awareness, a hedge fund founded by former OpenAI researcher Leopold Aschenbrenner, disclosed a 5.6% stake (12.4 million Class A shares). Nebius, spun out from Russian internet giant Yandex, provides GPUs for AI model training. The company has secured major partnerships, including a $27 billion deal with Meta in March and a $2 billion investment from Nvidia. Nebius shares are up 149% year-to-date, positioning it as a key AI compute provider in Europe.
US Top News and Analysis