This paper explores the profitability of portfolio-based momentum strategies. The data consists of all NYSE, AMEX, and NASDAQ stocks on the CRSP database. The analysis considers the period July 1963 to December 2002 and the tests are performed on portfolios formed on industry, size and...

We study effects of correlation ambiguity on portfolio choice when the number of risky assets is large. We find that the optimal portfolio contains only a fraction of available risky assets. With 100 stocks randomly selected from the S&P 500, less than 20 stocks will be held in the optimal...

We explicitly solve for the optimal dynamic strategy between a riskless asset and a risky asset with momentum. The optimal portfolio weight depends not only on momentum that characterizes the expected return as in Merton (1971) framework, but also on the historical price path, unlike in Merton....