September, 2015 – InvestorLiterature.com Review
“Active share” is a subject made famous by Martijin Cremers and Antti Petajisto of Yale in their original 2009 study, and followed - up in two 2013 studies. It has grown significantly in use and importance in active investment management. The application of the concept has been expanded from mainly large cap to include medium and small cap. In this Review we sum up the original papers on Active Share plus recent ones, including one which questions some of the original premises, followed by a reply by the original author Petajisto. Our overall conclusion is in support of the concept of Active Share and in agreement with the original work of Cremers and Petajisto.