Humanoid robot maker Unitree’s 460% surge in its Shanghai stock market debut on Wednesday was the latest in a series of eye-watering first trading-day pops fetched by some recent tech initial public offerings in mainland China’s stock market. It followed last month’s debut of ChangXin Memory Technologies, also known as CXMT, whose stock shot up 472% on its first trading day.

On the face of it, these extraordinary stock moves underscore Chinese investors’ euphoria about the tech sector and demonstrate the success of Beijing’s strategy of nurturing homegrown champions and cutting reliance on U.S. technologies. But that’s only part of the story.