Nebius rises after AI hedge fund Situational Awareness discloses 5.6% stake

Nebius shares surged 12% in premarket trading Thursday after AI-focused hedge fund Situational Awareness, led by former OpenAI researcher Leopold Aschenbrenner, disclosed a 5.6% stake in the AI cloud company. The fund reported owning 12.4 million Class A shares worth approximately $2.6 billion in a Wednesday SEC filing, positioning it among Nebius's largest institutional shareholders. The disclosure follows Nebius's recent momentum from major cloud contracts with Microsoft and Meta, as well as investments from Nvidia, with shares up 165% this year.

Nebius rises after AI hedge fund Situational Awareness discloses 5.6% stake Nebius https://robinhood.com/us/en/stocks/NBIS/?source=sherwood jumped 12% in premarket trading Thursday after Situational Awareness , the hedge fund run by former OpenAI researcher Leopold Aschenbrenner https://fortune.com/2025/10/08/leopold-aschenbrenner-openai-ftx-1-5-billion-hedge-fund-situational-awareness/ , disclosed a major stake in the AI cloud company. According to its 13G filed Wednesday https://www.sec.gov/Archives/edgar/data/2045724/000093583626000303/xslSCHEDULE 13G X02/primary doc.xml , the fund reported owning 12.4 million Class A shares of Nebius, representing a 5.6% stake worth ~$2.6 billion as of Wednesday’s closing price. The position didn’t appear in the fund’s most recent 13F filing — which covered holdings https://www.sec.gov/Archives/edgar/data/2045724/000204572426000008/xslForm13F X02/salp13fq1xml.xml as of March 31 and included other neocloud companies such as CoreWeave https://robinhood.com/us/en/stocks/CRWV/?source=sherwood and IREN https://robinhood.com/us/en/stocks/IREN/?source=sherwood — suggesting the Nebius stake was added sometime after the first quarter. The disclosure puts Situational Awareness among Nebius’s largest disclosed institutional shareholders , at least based on the latest available ownership filings https://www.nasdaq.com/market-activity/stocks/nbis/institutional-holdings , which show Blackrock as the largest institutional holder as of March 31, with 4.5% of shares outstanding. One of the "neocloud" stocks, Nebius has gained traction recently after securing large cloud contracts with Microsoft https://sherwood.news/markets/nebius-soars-new-report-details-importance-near-20-billion-microsoft-deal/ and Meta https://sherwood.news/markets/nebius-soars-signing-ai-infrastructure-deal-meta-worth-27-billion-5-years/ , as well as an equity investment from Nvidia https://sherwood.news/markets/nebius-spikes-after-announcing-usd2-billion-investment-from-nvidia/ and an energy partnership with Bloom https://sherwood.news/markets/nebius-soars-bloom-energy-deal-price-hike-rumors/ . Shares are up 165% this year and a whopping 475% over the past 12 months. Founded in 2024 by Aschenbrenner — and named after his widely-read essay https://fortune.com/2025/10/08/leopold-aschenbrenner-openai-ftx-1-5-billion-hedge-fund-situational-awareness/ on artificial superintelligence — Situational Awareness has built its portfolio around the physical infrastructure AI runs on, from chips and data centers to power and compute. Per its 13F filings, the fund’s reported portfolio value climbed to $13.7 billion https://www.sec.gov/Archives/edgar/data/2045724/000204572426000008/xslForm13F X02/primary doc.xml as of the first quarter, up nearly 2.5x from $5.5 billion https://www.sec.gov/Archives/edgar/data/2045724/000204572426000002/xslForm13F X02/primary doc.xml at the end of 2025.