X0306 4 2017-02-16 0 0000907654 ARCA biopharma, Inc. ABIO 0001365618 Hove Anders D 11080 CIRCLEPOINT RD., SUITE 140 WESTMINSTER CO 80023 1 0 0 0 Common Stock 767660 I By Venrock Healthcare Capital Partners II, L.P. Common Stock 311272 I By VHCP Co-Investment Holdings II, LLC Common Stock 390912 I By Venrock Healthcare Capital Partners, L.P. Common Stock 71487 I By VHCP Co-Investment Holdings, LLC Stock Option (right to buy) 2.50 2017-02-16 4 A 0 10000 0.00 A 2027-02-15 Common Stock 10000 10000 D These securities are owned directly by Venrock Healthcare Capital Partners II, L.P. The Reporting Person has a pecuniary interest in Venrock Healthcare Capital Partners II, L.P. The Reporting Person holds no voting or investment interest in these securities, and disclaims beneficial ownership of such shares except to the extent of his pro rata partnership interest therein. These securities are owned directly by VHCP Co-Investment Holdings II, LLC. The Reporting Person has a pecuniary interest in VHCP Co-Investment Holdings II, LLC. The Reporting Person holds no voting or investment interest in these securities, and disclaims beneficial ownership of such shares except to the extent of his pro rata partnership interest therein. These securities are owned directly by Venrock Healthcare Capital Partners, L.P. The Reporting Person has a pecuniary interest in Venrock Healthcare Capital Partners, L.P. The Reporting Person holds no voting or investment interest in these securities, and disclaims beneficial ownership of such shares except to the extent of his pro rata partnership interest therein. These securities are owned directly by VHCP Co-Investment Holdings, LLC. The Reporting Person has a pecuniary interest in VHCP Co-Investment Holdings, LLC. The Reporting Person holds no voting or investment interest in these securities, and disclaims beneficial ownership of such shares except to the extent of his pro rata partnership interest therein. Grant to the Reporting Person of a stock option under the 2013 Amended and Restated Equity Incentive Plan, vesting in 12 equal monthly installments beginning as of February 16, 2017. If the Reporting Person's service as a director of the Issuer terminates in connection with or at any time following a change in control (for whatever reason), then any unexpired options that remain unvested shall become fully vested /s/ Brian L. Selby, Attorney-in-Fact 2017-02-21