Trading Activity and Foreign Exchange Market Quality

This paper studies intraday market quality for currency pairs with very different trading characteristics, the Euro-U.S. dollar and the Canadian dollar-U.S. dollar. Two sets of tests - the first based on the ratio of long term to short term variances, and the second based on information spillovers - provide consistent conclusions regarding market quality. The variance ratio analysis shows that market quality is highest for the Euro during European trading and lowest during Asian trading. For the Canadian dollar, market quality is highest during North American trading and lowest during Asian trading. Analysis of information spillovers shows that innovations in returns and volatility for the more heavily-traded Euro predict returns and volatility for the Canadian dollar during Asian and European trading, but innovations for the dollar have predictive power for the Euro during North American trading. Our results suggest that foreign exchange market quality is high, not always when quoting and trading activity are heavy but rather, and somewhat unexpectedly, when activity is not only high, but also geographically focused and concentrated among a limited number of major dealers.