(Yicai Global) Jan. 17 -- The recent blockchain mania in China's A-share market has furrowed brows on the Shanghai and Shenzhen stock exchanges. The two bourses issued warning notices yesterday, and took scrutiny measures such as suspensions for queries, suspensions to cool down, and clarifications regarding related companies.

The stock prices of some companies had rallied following blockchain-related announcements, some even posed a risk of stock speculation, the two exchanges advised.

The two took notice of 10 and 17 blockchain-related stocks, respectively, per the announcement.

The stock price of Easysight Supply Chain Management Co. [SHA:600093] had reached its 10 percent daily limit up for four consecutive days, with a cumulative increase of 46 percent. The Shanghai exchange directed the company to suspend trading, disclose its blockchain-related business details and warn of risks.

Blockchain technology is still in its infancy, which complicates formation of a stable business model based thereon, and this is thus an obvious sign of share hysteria, said the Shanghai bourse, which will suspend trading in, disclose blockchain-related business details of and warn of risks if a company's shares suddenly spike in value, the exchange said.

It has also made listed firms state their involvement if any in blockchain-related businesses and suspend trading for clarification and undergo insider trading investigation. It will further discipline firms suspected of violating listing rules.

Shanghai will also order firms with businesses that have some nexus with blockchain technology to aver no direct relation between their business and blockchain technology, even if they have not yet started operating such businesses.

Shenzhen will closely attend to information disclosure and the secondary market trading of relevant companies, promptly sanction those using blockchain to mislead investors and report lawbreakers to China Securities Regulatory Commission for investigation, it said.

This scrutiny depressed blockchain stocks after today's opening of the A-share market. Beijing Ultrapower Software Co. [SHE:300002], Xiamen Anne Co. [SHE:002235], YGSOFT Inc. [SHE:002063] and others fell 10 percent right upon opening in their largest single-day decline. These stocks have skylarked in the past few days, logging large cumulative rises.