Together AI closes $800M Series C at $8.3B valuation, backed by Aramco on open-source AI boom
Together AI, an AI neocloud platform for training and running open-source models at scale, closed an $800 million Series C funding round on Wednesday, July 1, at an $8.3 billion post-money valuation. The round was led by Aramco Ventures and co-led by Saudi Arabia's Prosperity7 Ventures, with participation from Vista Equity Partners, General Catalyst, Emergence Capital, NVIDIA, Salesforce Ventures, March Capital, Pegatron, and SentinelOne's S Ventures. The valuation more than doubles Together AI's $3.3 billion Series B valuation from February 2025.
The company reported $1.15 billion in annualized bookings as of Q2 2026, up 250%+ from mid-2025 levels, and now serves thousands of paying customers. Together AI's platform offers 2–3x faster inference than hyperscaler solutions, supports 200+ open-source models across modalities (chat, image, audio, code, embeddings), and has become the default cloud for DeepSeek-R1, Llama, and other frontier open models. One enterprise customer reported cutting inference costs sixfold after migration, signaling the economic moat around open-source alternatives.
The capital influx supports expansion of Together AI's infrastructure, including deployment of NVIDIA Blackwell GPUs, 200MW of secured power capacity, and a partnership with Hypertec to co-build a 36,000-GPU GB200 NVL72 cluster. The round reflects investor confidence in the thesis that open-source model usage has tripled over the past 12 months and will capture price-sensitive enterprise demand as model capabilities converge toward proprietary alternatives.
For practitioners, Together AI's growth and funding signals a structural market shift: open-source models, once relegated to cost-cutting, are now viable for production inference at enterprise scale. This matters because it fragments the vendor lock-in that proprietary model providers (OpenAI, Anthropic) have built and creates a sustainable alternative for workloads where 6x cost reduction outweighs marginal capability differences. Watch whether Aramco's strategic participation signals Middle Eastern AI sovereignty plays, and whether competing neoclouds (CoreWeave, Vast.ai, Lambda Labs) face margin pressure.