After a nine-year career at trading desks in Europe and Asia, Marco Dion has more market experience than most stock-research analysts. As the European head of equity quantitative research at JP Morgan in London, Dion, 33, develops systematic trading strategies for hedgefund managers and was on the front lines of the 2008 financial crisis.

That ordeal reinforced Dion’s pragmatic approach to designing trading systems for individual stocks. As a trader he quickly learned the difference between being right and making money (or at least not losing it), a skill that helped him navigate last year’s turbulent markets.

"I have sympathy for anyone who lost money over the past two or three years," he says. "If you try to be rational in an irrational market, it isn’t going to work."