X0306 4 2018-12-17 0 0001269021 PORTOLA PHARMACEUTICALS INC PTLA 0001192591 HOMCY CHARLES J C/O PORTOLA PHARMACEUTICALS, INC. 270 EAST GRAND AVE. SOUTH SAN FRANCISCO CA 94080 1 0 0 0 Common Stock 2018-12-17 4 M 0 64218 4.10 A 176689 D Common Stock 2018-12-17 4 S 0 63518 18.602 D 113171 D Common Stock 2018-12-17 4 S 0 700 19.20 D 112471 D Common Stock 2018-12-19 4 M 0 25782 4.10 A 119480 I Charles Homcy Revocable Trust Common Stock 20000 I The Charles J. Homcy 2009 Grantor Retained Annuity Trust Stock Option (Right to Buy) 4.10 2018-12-17 4 M 0 24390 0.00 D 2008-12-23 2018-12-22 Common Stock 24390 0 D Stock Option (Right to Buy) 4.10 2018-12-17 4 M 0 39828 0.00 D 2008-12-23 2018-12-22 Common Stock 39828 25782 D Stock Option (Right to Buy) 4.10 2018-12-19 4 M 0 25782 0.00 D 2008-12-23 2018-12-22 Common Stock 25782 0 D The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 7, 2018. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $18.2000 to $19.1900, inclusive. These sales were sold in a single transaction at a price of $19.20. Dr. Homcy exercised these shares through a cash exercise and transferred the shares following the exercise into the Charles Homcy Revocable Trust for which Dr. Homcy is a trustee. /s/ Mike Ouimette, as attorney-in-fact 2018-12-19