China's domestic stock markets are dominated by individual, not professional, investors.VCG/Getty ImagesChina's stock markets slumped after a 10-day rally that was driven by Beijing's stimulus announcement in September.Investors were disappointed when a hyped-up Chinese government press briefing failed to deliver more stimulus.Retail investors dominate China's markets, influencing sentiment and market movements.China's top leadership has a problem with its economic stimulus: its own investors at home saw right through the hype this week.China's domestic stock markets slumped on Wednesday after a 10-day blitz culminated in a two-year high.The mainland's benchmark CSI 300 Index closed 7.1% lower, while leading indices in Shanghai and Shenzhen ended the day 6.6% and 8.7% lower.China's domestic stock markets are dominated by over 200 million mom-and-pop retail investors, who account for about 70% of the trading volume.