In a nutshell: China's two biggest gaming corporations, Tencent and NetEase, have lost a combined value of more than $60 billion dollars in the last 24 hours. That figure is eight times more than Microsoft paid to acquire Bethesda's parent company ZeniMax.
The stock rile up comes as China continues to overregulate the video game industry in China. Last month, Chinese officials mandated that children under 18 years of age can only play video games for a total of one hour on Fridays, weekends, or holidays. Previous rules allowed for 1.5 hours during the week and three hours on holidays and weekends.
State-run news outlet Xinhua News Agency notes that Chinese regulators met with industry leaders again this week, advising them to stop focusing on profits and begin making changes to game design that do not "induce additions."
"The authorities ordered the enterprises and platforms to tighten examination of the contents of their games," reported Xinhua. "Obscene and violent content and those breeding unhealthy tendencies, such as money-worship and effeminacy, should be removed."
Additionally, the Chinese government has reportedly begun limiting the number of licenses it issues for online games. State-run South China Morning Post notes that the agency handling such licensing—the National Press and Publication Administration—is prompt about releasing lists of approved titles at the end of each month. However, it has not yet revealed its approved list for August.
While NetEase has not commented on the recent meetings or the stock plummet, Tencent spoke with Bloomberg, saying it agrees with regulators.
"We believe in healthy gameplay and take very seriously the physical and mental health of minors," Tencent told Bloomberg in a statement. "We appreciate the guidance and instruction from the relevant regulators and will work hard to be in full compliance with all rules relating to youth game addiction and content regulation."