We explore the sharp uptrend in recent trading activity and accompanying changes in market efficiency. Higher turnover has been associated with more frequent smaller trades, which have progressively formed a larger fraction of trading volume over time. Evidence indicates that secular decreases...

Market efficiency, the timely incorporation of information into prices, remains a central and controversial issue in finance. The short-horizon predictability of returns from past order flows is an inverse indicator of efficiency. We analyze this predictability for NYSE stocks that traded every...

Daily returns for stocks listed on the New York Exchange (NYSE) are not serially dependent. In contrast, order imbalances on the same stocks are highly persistent from day to day. These two empirical facts can be reconciled if sophisticated investors react to order imbalances within the trading...

We focus on an intuitive measure of trading activity: the aggregate daily order imbalance, buy orders less sell orders, on the NYSE. Order imbalance increases following market declines and vice versa, which reveals that investors are contrarians in aggregate. Order imbalances in either...

Daily returns for stocks listed on the New York Exchange (NYSE) are not serially dependent. In contrast, order imbalances on the same stocks are highly persistent from day to day. These two empirical facts can be reconciled if sophisticated investors react to order imbalances within the trading...

Spreads, depths and trading activity for US equities are studied over an extended time sample. Daily changes in market averages of liquidity and trading activity are highly volatile, negatively serially correlated and influenced by a variety of factors. Liquidity plummets significantly in down...

Traditionally and understandably, the microscope of market microstructure has focused on attributes of single assets. Little theoretical attention and virtually no empirical work has been devoted to common determinants of liquidity nor to their empirical manifestation, correlated movements in...

Daily returns for stocks listed on the New York Exchange (NYSE) are not serially dependent. In contrast, order imbalances on the same stocks are highly persistent from day to day. These two empirical facts can be reconciled if sophisticated investors react to order imbalances within the trading...

Traditionally, volume has provided the link between trading activity and returns. We focus on a hitherto unexplored but intuitive measure of trading activity: the aggregate daily order imbalance on the New York Stock Exchange. Signed order imbalances increase (decrease) following market declines...