AI inference startup Baseten reportedly raising $1.5B months after its last mega round

AI inference startup Baseten is close to finalizing a $1.5 billion funding round at a $13 billion valuation, just five months after raising $300 million at a $5 billion valuation. The round is split-priced, with some investors coming in at $13 billion and others at $11 billion, co-led by Spark Capital, Sands Capital, Altimeter Capital, and Wellington Management. Baseten benefits from the AI inference gold rush, offering cost-effective model routing for inference tasks.

AI inference company Baseten is close to finalizing a stunning $1.5 billion funding round at a $13 billion valuation, the WSJ reports. https://www.wsj.com/tech/ai/the-13-billion-ai-startup-betting-on-cheaper-alternatives-to-openai-anthropic-b9679603?mod=tech lead pos1 Just five months ago, the startup announced that it had raised a $300 million Series E https://www.baseten.co/blog/announcing-baseten-s-300m-series-e/ at a $5 billion valuation. And that round was just nine months after raising a $150 million Series D. https://www.baseten.co/blog/announcing-baseten-150m-series-d/ If finalized, this latest round would represent a 160% increase in valuation in less than half a year. However, the WSJ reports that this is a split-priced round https://techcrunch.com/2026/03/03/why-ai-startups-are-selling-the-same-equity-at-two-different-prices/ , a tactic startups are using to boost their headline valuation and make lead investors look good on paper. Some investors in this latest funding round are reportedly coming in at a $13 billion valuation, while others at $11 billion, sources told the Journal. This deal is said to be co-led by Spark Capital, Sands Capital, Altimeter Capital, and Wellington Management. Launched in 2019, Baseten is a startup benefiting from what The Next Wave hailed the “inference gold rush,” https://thenextweb.com/news/baseten-1-5bn-round-13bn-valuation-ai-inference in which VCs are pouring enormous amounts of money into companies building the inference layer. Inference is what the model does after a user submits a prompt. Baseten promises to handle inference quickly while controlling costs by routing requests to the best-for-task model, especially to competent, less-expensive open source alternatives.