Joel Greenblatt is best known for his Magic Formula, an investment technique that combines quality and value. Greenblatt's own research shows the magic formula investing strategy averaged 24% returns per year between 1988 and 2009. Sign up now and get our in-depth FREE e-books on famous investors like Klarman, Dalio, Schloss, Munger Rupert is a committed value investor and regularly writes and invests following the principles set out by Benjamin Graham. He is the editor and co-owner of Hidden Value Stocks, a quarterly investment newsletter aimed at institutional investors.