One of America’s wealthiest men was among six hedge fund managers and corporate executives arrested Friday in a hedge fund insider trading case that prosecutors say reaped more than $20 million in illegal profits and should be a wake-up call for Wall Street.

Raj Rajaratnam, a partner in Galleon Management and a portfolio manager for Galleon Group, a hedge fund with up to $7 billion in assets under management, was accused of conspiring with others to trade based on insider information about several publicly traded companies, including Google Inc.