Naive AI, a Beijing-based large language model startup founded by Tsinghua University associate professor Dai Jifeng, has raised $400 million across three funding rounds at a $1.42 billion valuation. Investors include Tencent, IDG Capital, and HSG (formerly Sequoia Capital China). Rather than pretraining a model from scratch, Naive AI is modifying an existing open-weight Chinese model and plans to release its own model as freely downloadable open weights.