The company, which beat analyst estimates on both the top and bottom lines, said completed Cologuard test volume rose 149 percent to 135,000 tests.
The Index was up about 4 percent month over month and outpaced the Dow Jones Industrial Average and the Nasdaq Composite, but trailed the Nasdaq Biotechnology index.
The proceeds from the offering will be used to fund the expansion of commercialization activities for the firm's colon cancer test, Cologuard.
Along with Exact, Natera and Qiagen saw sharp spikes in their stock prices, while Invitae and Opko Health each saw their share prices drop by more than 20 percent.
The decision is a quick reversal from a recent decision by the insurer not to cover fecal DNA testing and makes it the final major US insurer to cover Cologuard.
First quarter results that blew away analysts' estimates lifted Exact Science's stock, while Abbott's new deal with Alere sparked that firm's share price.
The company, which beat Wall Street expectations on the top and bottom lines, said completed Cologuard test volume rose 150 percent over Q1 2016.
The investment bank gave Exact Sciences' shares a price target of $30, and said it expects higher uptake of the Cologuard test and an increase in payor contracts.