China's stocks surged on Thursday, sending the benchmark index to its biggest two-day gain in 18 months, amid speculation the government may act to stabilize economic growth.

The benchmark Shanghai Composite Index, which covers both A and B shares, ended up 3.23 percent, or 64.86 points, at 2072.99 points.

And the Shenzhen Component Index also surged 4.25 percent to 8184.77 points, its biggest gain in 18 months, while the Hang Seng China Enterprises Index climbed 3.65 percent.

Securities companies led the advance.

Financial stocks were among the biggest gainers on China's bourses, with Haitong Securities Co and China Minsheng Banking Corp soaring by the daily 10 percent limit in Shanghai market, while Hong Yuan Securities Co and Ping An Bank Co also rose 10 percent in Shenzhen market.