X0306 4 2019-04-04 0 0001269021 PORTOLA PHARMACEUTICALS INC PTLA 0001574591 Dier Mardi C/O PORTOLA PHARMACEUTICALS, INC. 270 EAST GRAND AVENUE SOUTH SAN FRANCISCO CA 94080 0 1 0 0 EVP, CFO & CBO Common Stock 2019-04-04 4 S 0 40486 37.3913 D 66733 D The sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 5, 2019. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $37.1000 to $37.7400, inclusive. The reporting person undertakes to provide Portola Pharmaceuticals, Inc., any security holder of Portola Pharmaceuticals, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) to this Form 4. /s/ Mike Ouimette, as attorney-in-fact 2019-04-08