We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM) for a large number of alphas. To compute alpha allocation weights, one then resorts to...

Short sellers are perceived as informed, sophisticated investors. Yet little is known about their actual performance and trading strategies. Using a novel, hand-collected data set of daily position disclosures in Europe, we identify the entry, change, and exit dates of large short-sale positions...