Tanium Inc., the highly valued and highly controversial security software company, is selling $100 million of common stock in an apparent bid to enable early investors to cash in some of their shares.

The new funding round is being led by TPG Growth, which was an early investor in the firm. It brings Tanium’s total fundraising to more than $400 million on an estimated market capitalization of $3.7 billion.

The move is unusual in that Tanium is not selling preferred shares, which give shareholders special rights, but common stock that investors can cash out immediately. One of those investors David Hindawi, who co-founded the company in 2007 with his son and Chief Executive Orion (pictured). In an interview with CNBC, Orion Hindawi said his father is planning to invest about $50 million of the proceeds into a charitable foundation that he declined to name.

The funding raised some eyebrows in the Silicon Valley venture capital community because Tanium claims to have more than $300 million in cash and investments already, over 100 percent revenue growth and positive operating cash flow. It has made no secret of its intentions to go public, but said it will do so on its own timetable.

In the meantime, recent tumult at the organization prompted Fortune to characterize it as “the Uber of cybersecurity companies” and Bloomberg to call it a “family empire in crisis.” The management style of Tanium’s irascible CEO reportedly prompted a recent exodus of at least nine top executives, including its president, chief marketing officer, chief accounting officer and the heads of operations and finance. A Bloomberg investigation reported that Orion Hindawi has fired workers before they can cash in their stock options in order to strengthen his hold on the company and that he frequently ridicules and insults employees in public.

Orion Hindawi had to apologize last month for exposing a customer’s network during sales pitches. However, he defended himself against charges of engendering a “toxic” culture. Tanium is “mission-oriented, hard-charging, disciplined, even intense, but not toxic,” he wrote in an open letter.

The turmoil continued earlier this month as Tanium and VMware Inc. acknowledged that a much-ballyhooed original equipment manufacturer relationship between the two firms had been quietly ended after less than a year.

Despite the histrionics, Tanium has succeeded in building a blue-chip client list and a massive venture-capital war chest. The company’s endpoint management product can reportedly detect activity on any endpoint in seconds to quickly isolate threats and shut them down. It can also manage patches, software distribution, asset inventory and utilization. Former Microsoft executive Steven Sinofsky, who is an adviser to venture capital firm Andreessen Horowitz, once called Tanium’s technology “magic.”

Image: Tanium