Xia Yuan, 28, a sales manager at Shanghai Yikang Trade Co Ltd, has received several e-mails from the company's administration department saying that stock trading during work hours is "strictly banned".

Xia said he has received such e-mails three times in the past four months. The company's IT specialists also have blocked access to several websites which provide real time stock market information.

"The upheaval in the stock market seems to have involved everyone in our company. Everybody talks about the stock market during work time, after work, and even during holidays via social media tools like WeChat," said Xia.

Workers gazing at the changing prices of stocks they hold during the four hours of trading in a day could be easily spotted in many enterprises across the country.

In Guangzhou, Guangdong province, an Internet financing company has circulated notes warning that workers who trade stocks during work time may be subject to penalties ranging from a 30 percent salary cut to dismissal, reported the Guangzhou-based Southern Metropolis Daily.

In mid-June, the benchmark Shanghai Composite Index surged to a seven-year high, piercing through the 5,000-point level for the first time since 2008. But in the past two weeks, the indicator has fallen by more than 1,000 points, and closed at 4,053.03 points on Monday.

"You really need to stare at the data in order not to miss the window of buying and selling," said Wang Yue, a 52-year-old high school teacher in Hangzhou, Zhejiang province.

"In June it was really tough for fully employed professionals like me to keep track of the market movements. Stock investment requires full-time attention, but I can't stare at data and news that affect the market when I am in a classroom. Hopefully, the summer holidays will begin soon," said Wang.

Many employers, however, said that blocking stock information websites or circulating warnings have not deterred employees from trading in stocks during work hours.