New draft regulations issued Friday proposed a slew of measures to limit the amount of time and money players spend online. For investors, that brought back memories of 2021, when regulators limited online gaming to three hours a week for minors—and of China’s broader tech crackdowns since late 2020.

Stock in Tencent, the gaming and social-media giant, sank 12%.

Smaller rival NetEase dropped 25%, marking its biggest daily decline since it obtained a Hong Kong listing in 2020.

The wider Hang Seng Tech Index fell 4.4%.

In Europe, stock in Tencent shareholder Prosus crashed 18%. France’s Ubisoft dropped 5%.

U.S.-listed Chinese stocks and exchange-traded funds looked likely to come under pressure. The KraneShares CSI China Internet ETF, or KWEB, fell more than 6% in premarket trading.