The rules of the game keep getting harder for China’s internet sector.

On Friday, Tencent lost $46 billion in market value as Chinese gaming stocks traded in Hong Kong dropped, hurt by Beijing’s newly released draft regulations for the online games industry. It was Tencent’s biggest tumble in more than 10 years. Smaller competitor NetEase lost around $16 billion in value. The new proposed rules include restrictions on incentives to play or spend more online. They are the latest salvo in China’s fight against gaming addiction, which had earlier driven it to freeze new game approvals and launch investigations into their content.