Shares related to brain-computer interface (BCI) in Chinese A-share market surged on Tuesday, after Tesla's CEO Elon Musk said on Twitter that he has "already" uploaded his brain to the cloud. 

The share price of Shanghai-based ENC Digital Technology Co, an industry cognitive solutions provider, closed at 8.6 yuan ($1.28) at Tuesday, hitting its daily limit. Another related company Innovative Medical also saw its share price hit daily limit, closing at 6.49 yuan on Tuesday.

In response to a question tweeted by Dogecoin founder Billy Markus on Tuesday "if you could upload your brain to the cloud, and talk to a virtual version of yourself, would you be buddies?" Musk tweeted that he "already did it." 

The tweets later sparked discussion among netizens on Chinese social media platform Weibo. Some doubted the claim, saying that it could be just hype; while some said that, without proper supervision and constraints, AI and biotechnology's development could be dangerous for human being in the future.

"Musk was presumably referring to his neurotechnology company, Neuralink," US-based financial news platform Benzinga reported. 

Neuralink Corporation is a neurotechnology company that develops implantable brain-machine interfaces. Musk co-founded the company in 2016. He tweeted on April 9, 2021 that the company's first product "will enable someone with paralysis to use a smartphone with their mind faster than someone using thumbs," and "the device is implanted flush with skull and charges wirelessly, so you look and feel totally normal." 

BCI technology is one of the most advanced technologies in the world in recent years, which can be applied to medical, education, games, smart home, military and other applications.

It is estimated that the scale of China's BCI market is expected to reach 125 billion yuan by 2040, with a compound annual growth rate of 26 percent, media reports have claimed, citing an industrial analysis.