Upwind Security raised $400.0M at a $3.8 billion valuation, according to Bloomberg's October 28, 2026 headline "AI Cybersecurity Startup Upwind Raises at $3.8 Billion Value." The provided article source contains only Bloomberg navigation boilerplate and no body text, so specific details on whether this is a first or follow-on round, metrics such as clients, revenue, pipeline or employee count, planned use of funds/expansion plans, and key investors were not available in the supplied content and cannot be verified.