China's stock capitalization will account for 20 percent of global stocks by 2030, up from 6 percent in 2012, according to a report on Tuesday forecasting the global economy in 2030 by Standard Chartered Bank.

The United States, with 21 percent, is forecast to remain in the lead.

The report highlights three reasons for stock market expansion.

Companies in developing countries rely heavily on stock capitalization for financing.

The privatization of State-owned enterprises will drive stock market growth. And finally, investors, in greater numbers, will come into the market.