Once upon a time, the mere mention of the California Public Employees Retirement System could make any executive break into a sweat and wonder: What does CalPERS want now?

Mention the $239 billion pension fund giant these days and you’re likely to hear a different question: What the heck is going on over there?

In less than six months, four top executives have left the mighty CalPERS, long regarded as the heaviest of heavyweights in shareholder activism. The fund actually lost money for the year ending June 30, the first time that’s happened in years. Granted, $239 billion still goes ...