We find that subsequent to both US and domestic market gains, both Asian individual and institutional investors increase their trading and that this effect is more pronounced in bull markets, in periods of relatively favorable investor sentiment, in periods of extremely high market returns, and in markets with short-sale constraints. We also find that individual investors trade more in response to market gains than institutional investors. Moreover, we find that further integration of Asian stock markets with US stock markets after the Asian financial crisis in 1998 is an important reason for Asian investors' response to US market gains. ? 2013 Financial Management Association International.