We show that equity markets are typically two-sided and that trades cluster in certain trading intervals for both NYSE and Nasdaq stocks under a broad range of conditions-news and non-news days, different times of the day, and a spectrum of trade sizes. By "two-sided" we mean that the arrivals...

In this paper, we infer motives for trade initiation from market sidedness. We define trading as more two-sided (one-sided) if the correlation between the numbers of buyer- and seller-initiated trades increases (decreases), and assess changes in sidedness (relative to a control sample) around...