Why did NVDA move on Jun 30, 2026?

Nvidia's stock experienced a brief pullback and heightened volatility around 10:07 ET following reports that OpenAI engineers developed new software optimizations that cut model inference costs by more than 50% [1], [2]. This development was flagged as a potential headwind for Nvidia because the increased efficiency means OpenAI will require fewer of Nvidia's graphics chips to run its AI models [2]. Although the stock ultimately closed higher on the day, this specific technological breakthrough by a major AI customer served as a localized negative catalyst during morning trading [2], [3].