Ellie Mae Inc. shares soared 19% in premarket trade Tuesday after the company said it has agreed to be acquired by private-equity firm Thoma Bravo in a deal with an equity value of about $3.7 billion. Under the terms of the agreement, Thoma Bravo will pay Ellie Mae shareholders $99 in cash per share, equal to a 47% premium over the 30-day average closing share price and 49 percent premium to the 60-day average closing price as of February 1, 2019.