X0306 4 2018-02-23 0 0001124140 EXACT SCIENCES CORP EXAS 0001306119 Conroy Kevin T C/O EXACT SCIENCES CORP. 441 CHARMANY DRIVE MADISON WI 53719 1 1 0 0 President and CEO Common Stock 2018-02-23 4 M 0 34325 0.00 A 864377 D Common Stock 2018-02-24 4 M 0 19500 0.00 A 883877 D Common Stock 2018-02-26 4 S 0 25319 42.338 D 858558 D Common Stock 25580 I Held in 401(K) Account Common Stock 65189 I Held in Grantor Retained Annuity Trust Restricted Stock Units 2018-02-23 4 M 0 34325 0.00 D Common Stock 34325 102975 D Restricted Stock Units 2018-02-24 4 M 0 19500 0.00 D Common Stock 19500 0 D Represents shares of common stock received upon vesting of a restricted stock unit award. Represents shares sold pursuant to a Sell-to-Cover Rule 10b5-1 Plan to pay withholding taxes due in connection with the vesting of certain restricted stock units on February 23, 2018 and February 24, 2018. In addition to the shares of Common Stock and restricted stock units reported on this Form 4, which total 1,052,302 shares, Mr. Conroy also holds, in the aggregate, an additional 1,131,872 vested and unvested options to purchase shares of Common Stock and restricted stock units, with each restricted stock unit representing a contingent right to receive one share of Common Stock. Each restricted stock unit represents a contingent right to receive one share of common stock. Represents a restricted stock unit award granted on February 23, 2017 that partially vested on February 23, 2018. The restricted stock units vest in four equal annual installments beginning on February 23, 2018. Represents a restricted stock unit award granted on February 24, 2014 that partially vested on February 24, 2018. The restricted stock units vest in four equal annual installments beginning on February 24, 2015. /s/ Kevin T. Conroy by Mark R. Busch, attorney-in-fact 2018-02-27