The stimulus measures could push China's GDP to grow as much as 5% next year, strategist said.

Chinese stocks could soon surge 15%, with another expected round of stimulus spurring a fresh economic growth spurt for the world's second-largest economy, according to Société Générale.

Strategists at the bank pointed to China's recent monetary stimulus package, which included measures like interest rate cuts, lowering reserve requirements for banks, and a $114 billion liquidity injection into China's economy.

Those measures boosted investors' optimism, with Chinese stocks notching their best week since the Great Financial Crisis after the measures were announced.

And there's likely more upside on the way, given that Beijing is likely to supplement the monetary support measures with increased fiscal spending next year, SocGen said. For stocks, that means a 15% jump from current levels in the near term, the bank said.

Strategists estimated that the stimulus package could be announced as soon as October, potentially at the next Standing Committee of the National People's Conference at the end of the month. The package could amount to as much as 3 trillion yuan, or $427 billion, and include an "open-ended commitment" for a bigger stimulus package the following year.

Those measures could push GDP growth to 5% next year, the strategists said, up from the bank's original estimates of 4.5% growth.

"The undervaluation of China equities is something that we observe across different benchmark indices and sectors. Most markets are trading well below or within their 10-year history," the bank said, adding that they also expected the policy to boost corporate earnings growth to as much as 15%.

"The exact magnitude of the boost will be subject to the size and details of the fiscal package ... the sustainability of housing stabilization and household wealth recovery."

Other experts have noted that China's monetary stimulus measures are unlikely to be effective without fiscal stimulus to go along with it. That could mean the latest stimulus package won't have any direct effect on Beijing's economy until 2025, the soonest funds will be made available and deployed, one researcher said this week.