According to Quartz and FinSMEs, Fireworks AI raised $1.5 billion in a Series D round on July 16, valuing the inference-infrastructure startup at $17.5 billion. The round was led by Atreides Management, Index Ventures, and TCV, with Nvidia and Lightspeed among the returning backers. Fireworks says its annualized revenue run rate has passed $1 billion, up roughly fivefold year-over-year, while daily token volume on its platform jumped from 15 trillion to more than 40 trillion. The company specializes in running open-weight models quickly and cheaply for enterprises, a niche that has become lucrative as businesses look to cut inference costs. The raise is another sign the money in AI is flowing not just to model makers but to the plumbing underneath them. Worth watching: whether inference margins hold as competition intensifies.