Shares of Stamps.com (NASDAQ:STMP) soared 64% on Friday after the shipping-services leader announced it struck a deal to be acquired by private equity firm Thoma Bravo. So what The all-cash deal values Stamps.com at roughly $6.6 billion. If the transaction is completed, shareholders will receive $330 in cash for each share they own, a 67% premium over Stamps.com's closing share price on Thursday. Thoma Bravo hopes to make Stamps.com its latest acquisition. Image source: Getty Images. The deal gives Stamps.com's board of directors a 40-day period to shop for a better offer. Still, the transaction is expected to close in the third quarter, subject to regulatory and shareholder approval.