National stock prices have the tendency to follow a common trend over the long term. However, short-run variations occur due to peculiarities inherent in national markets. The stochastic patterns followed by US stock prices and those of five other Pacific rim countries are examined for commonalities and differences using Johansen's maximum likelihood estimation method. The weekly national stock price indices used were obtained from The Far Eastern Economic Review for the period 1985 to 1992. The results indicate that the series are nonstationary, but cointegrated in two cases. In addition, all six stock variables have four common unit roots that largely determine long-term movements. However, evidence indicates that the US and Taiwan markets are distinct from the other four, which form a 'common' stock region. The facility with which short-run adjustments to temporary shocks are made simultaneously depends upon commonalities between market backgrounds.