Recent Wins for 401(k) Investors Signal New Class Defense Tactic

401(k) investors are on a hot streak—in court.

Employees who file lawsuits claiming retirement plan mismanagement have notched an impressive string of victories at the class certification stage. Twenty such cases—including those against Northrop Grumman, Franklin Templeton, and Oracle Corp.—have won class action status in recent years, while only two lawsuits saw class certification motions denied, a Bloomberg Law analysis found.

Employees with pending lawsuits against JPMorgan, CenturyLink Inc., and American Airlines Inc. are trying to keep the streak alive.

In cases involving thousands or tens of thousands of individual investors, winning class status can ...