Hong Kong (CNN Business) The Chinese government is trying to dampen demand for local tech stocks after President Xi Jinping personally endorsed blockchain technology, sending their value soaring.

Stocks of almost 200 companies that invest in blockchain technology jumped around 8% on Monday, according to an index compiled by East Money Information, with some very quickly hitting their daily limit of a 10% increase.

The spike came three days after Xi called for faster development of the blockchain sector, according to Chinese state-run news agency Xinhua.

"(Xi) stressed the importance of stepping up research on the standardization of blockchain to increase China's influence and rule-making power in the global arena," Xinhua said.

According to two inquiries sent by the Shanghai Stock Exchange and seen by CNN Business, companies involved in blockchain services were asked to better explain their businesses and keep their official statements factual and simple to avoid hype.

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