The Week’s 10 Biggest Funding Rounds: A Pair Of Billion-Dollar Deals For Cyber And AI Infrastructure Lead

intel — want to keep track of the largest startup funding deals in 2026 with our curated list of $100 million-plus venture deals to U.S.-based companies? Check out The Crunchbase Megadeals Board.

This is a weekly feature that runs down the week’s top 10 announced funding rounds in the U.S. Check out last week’s biggest funding deal roundup here. AI once again dominated venture funding this week, claiming five of the 10 largest announced rounds, including a pair of billion-dollar financings for AI infrastructure and cybersecurity that led the pack. Investors also continued to back quantum computing, geothermal energy, crypto infrastructure and aerospace startups with large checks. Let’s take a look. 1. (tied) Keyfactor, $1B, cybersecurity: Keyfactor raised a $1 billion private equity round led by Summit Partners. Other investors in the private equity round for the Independence, Ohio-based company included Insight Partners and Sixth Street Growth. Keyfactor provides digital identity and machine identity management software that helps enterprises secure certificates, encryption keys and connected devices. It has now raised $1.21 billion to date, per Crunchbase. 1. (tied) SambaNova, $1B, AI infrastructure: Palo Alto, California-based SambaNova officially announced a long-awaited $1 billion Series F deal at an $11 billion post-money valuation led by General Atlantic. A very long list of other investors joined the round, including Battery Ventures, BlackRock, Capital Group, Intel Capital, Qatar Investment Authority, T. Rowe Price and Vista Equity Partners. SambaNova develops AI chips and enterprise AI infrastructure for training and inference workloads.