The Chinese stock market is known for high synchronicity and the market portfolio represents a prominent risk factor to investors in the Chinese stock market. We conjecture that as a result, stocks with high exposure to market risk in China earn higher returns. Indeed, we find that CAPM beta is positively related to daily and monthly stock returns in the Chinese stock market. To substantiate our argument, we further show that the betareturn relation is stronger during periods when market risk is high. Moreover, we find that market risk is priced only during the day but not overnight in the Chinese stock market. We explore the effect of several unique trading rules in China and show evidence that the “T+1” trading rule is likely the cause.