This paper examines the impact of price limits on stock returns and volatility traded on the Taiwan Stock Exchange. We show that under price limits the observed stock returns are serially correlated and conditionally heteroscedastic. The empirical results do not support the hypothesis that price limits have a cool-off effect on stock returns. In particular, unlike previous studies suggesting that price limits reduce stock return volatility, we found that the volatility following limit moves increases, suggesting that price limits may be useless.