Months of speculation over the future of data security company Varonis Systems Inc. ended today when Thoma Bravo-owned cybersecurity firm Proofpoint Inc. agreed to buy it for about $6.3 billion in cash.

Bloomberg first reported in June that Varonis was fielding early interest from private equity firms, among them Blackstone Inc., Thoma Bravo and Vista Equity Partners. Proofpoint turned up as the buyer in talks in a second Bloomberg story in early September. Measured against the stock’s price before any of that reporting, the $49.75 a share Proofpoint is paying works out to a 52% premium.

The company being sold dates to 2005, when Yaki Faitelson, who still runs Varonis as chief executive, co-founded it with Ohad Korkus. Early versions of the software mapped who could open which files on corporate file servers. Artificial intelligence security now sits at the center of its pitch.

The deal is the largest in a run of acquisitions Proofpoint has made since Thoma Bravo paid $12.3 billion to take it private in 2021. German Microsoft 365 security provider Hornetsecurity GmbH was among last year’s purchases. Email threat protection, the market Proofpoint started in, became a Varonis business as well in September 2025, when Varonis agreed to buy phishing detection company SlashNext Inc.

Varonis’ data mapping and access controls are meant to slot in next to Proofpoint’s email, collaboration and data loss prevention products as one platform. More than 80 of the Fortune 100 already use Proofpoint, according to the company.

“As AI becomes embedded across the enterprise, the data it can access determines both its value and its risk,” Proofpoint Chief Executive Sumit Dhawan said. AI agents are now reaching into sensitive information and taking action across systems, he added. The combined company will serve more than 16,000 enterprises, and Proofpoint intends to move quickly after closing to integrate products and sales teams.

A committee of independent Varonis directors ran the sale process, and Faitelson said it reached out to “a range of potential strategic and financial buyers.” He called the deal “an excellent outcome for the company and our shareholders.”

The price, Faitelson said, is worth more than Varonis could have delivered under its “standalone plan” once risk is taken into account. By the companies’ own math, Proofpoint is paying about 8.4 times what Varonis brought in over the past 12 months. On free cash flow the multiple is about 53.

Varonis’ board approved the agreement unanimously. Nothing closes until regulators and Varonis shareholders sign off, and the companies expect to get there in the first half of 2027, at which point the stock comes off the Nasdaq. Thoma Bravo is putting up the equity and has lined up debt financing for the purchase, with Ontario Teachers’ Pension Plan Board also investing in Proofpoint.

Image: Varonis