Naive AI, a Beijing-based startup founded in February 2026 by Tsinghua University associate professor Dai Jifeng, has raised roughly $400 million across three funding rounds and reached a $1.42 billion valuation. Tencent, IDG Capital, MPCi and HSG, formerly known as Sequoia Capital China, participated in the financing. Rather than pretraining new foundation models, Naive AI focuses on improving existing open-weight models through mid-training, post-training and reinforcement learning. The company has fewer than 100 employees and plans to release its first open-weight large language model as early as September 2026. Dai previously worked at Microsoft Research Asia and SenseTime and left MiroMind in early 2026 after public disputes involving intellectual property and operations.