BlackRock 401(k) Investment Suits Send Message ‘Nobody’s Safe’

A flurry of new 401(k) lawsuits challenging companies that offer their workers conservative, low-cost target-date funds has enraged retirement industry insiders who say the complaints mean no retirement plan is safe from litigation.

The class actions are leveled at major companies defaulting employee investments into a suite of BlackRock Inc. index funds that automatically de-risk investments according to a specific target date—usually when investors are expected to retire.

Participants in Microsoft Corp., Capital One Financial Corp., and Marsh & McLennan Cos. Inc. plans, among others, claim their current or former employers chased low fees by offering BlackRock investments ...