HedgeCo.net reports that Nebius Group, the AI infrastructure company trading under the ticker NBIS, surged roughly 10% after a regulatory disclosure showed that Situational Awareness LP, an investment firm led by former OpenAI researcher Leopold Aschenbrenner, had taken a 5.5% passive stake. HedgeCo.net frames this event as part of an emerging “OpenAI Effect” in public markets, where disclosures by technically fluent, AI-native investors are being read as validation of companies in the AI infrastructure supply chain. The article argues that technical credibility from AI insiders can move prices and reshape investor attention toward compute, cloud, and model-deployment infrastructure.