Thoma Bravo to acquire Proofpoint in $12.3 billion deal Events About If you already have an account please use the link below to sign in. If you have any problems with your access or would like to request an individual access account please contact our customer service team. It is the largest-ever acquisition of a cloud firm by venture capital Thoma Bravo to acquire Proofpoint in $12.3 billion deal Private equity investment firm Thoma Bravo has entered into a definite agreement to acquire cyber security vendor Proofpoint, in a deal valued at $12.3 billion (£8.9 billion). As part of the all-cash transaction, Thoma Bravo will pay a 34 per cent premium over Proofpoint's closing share price on 23rd April ($131.78), with Proofpoint shareholders set to receive $176 (£127) per share in cash.