As stock markets tumble, company insiders are loading up big time. That’s one bullish sign amidst all the gloom (insider trading is most predictive for 12-month periods, according to studies).

Studies show insider trading is a useful guide for investment decisions. But some insider transactions are better signals than others. A recent study by Giamouridis, Liodakis, and Moniz identifies those with the "highest possible information content" and shows how to use them to develop “portfolio strategies that have economically and ...