An increasing volume of experienced trading tends to reduce autocorrelation and make the market more efficient. Autocorrelation in daily returns changes over time and the changes were less frequent than would be expected if the changes were random, but the changes are random recently. Autocorrelation has a negative connection with rate of return. The relation between autocorrelation and trading volume is positive and nonlinear.
Anthony Yanxiang Gu. "Increasing Block Transactions and Stock Market Behavior." New York Economic Review. vol. 33, Fall 2002, p. 67-74
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