Jay Cohen  BofA Merrill Lynch Global Research The buy side says: “Jay’s ability to distill complex issues is unmatched.”

This month, Jay Cohen celebrates his 46th birthday and his return to the top of the lineup after one year in second place. The BofA Merrill Lynch Global Research analyst wins plaudits for his “ability to focus on the details that drive performance,” as one fan puts it. That talent was on display when Cohen upgraded Aon Corp. from neutral to buy in July 2010, at $36.30, on the belief that the market had unfairly discounted the Chicago-­based insurance brokerage on news that it would acquire employee benefits manager Hewitt Associates of ­Lincolnshire, Illinois. By late August 2011 the stock had rallied to $46.73; its 28.7 percent advance was ahead of the Standard & Poor’s sector benchmark index by 45.7 percentage points.