X0609 4 2026-08-17 0 0001159036 HALOZYME THERAPEUTICS, INC. HALO 0001528185 Torley Helen false C/O HALOZYME THERAPEUTICS, INC. 12390 EL CAMINO REAL SAN DIEGO CA 92130 1 1 0 0 PRESIDENT AND CEO 1 Common Stock 2026-08-17 4 M 0 20000 18.41 A 787780 D Common Stock 2026-08-17 4 S 0 900 98.958 D 786880 D Common Stock 2026-08-17 4 S 0 500 100.457 D 786380 D Common Stock 2026-08-17 4 S 0 2100 101.766 D 784280 D Common Stock 2026-08-17 4 S 0 9000 102.553 D 775280 D Common Stock 2026-08-17 4 S 0 7500 103.482 D 767780 D Common Stock 2026-08-18 4 M 0 20000 18.41 A 787780 D Common Stock 2026-08-18 4 S 0 5703 103.083 D 782077 D Common Stock 2026-08-18 4 S 0 4897 104.11 D 777180 D Common Stock 2026-08-18 4 S 0 9400 104.874 D 767780 D Common Stock 2026-08-19 4 M 0 20000 18.41 A 787780 D Common Stock 2026-08-19 4 S 0 7200 106.358 D 780580 D Common Stock 2026-08-19 4 S 0 9600 107.224 D 770980 D Common Stock 2026-08-19 4 S 0 3200 107.765 D 767780 D Option to Purchase Common Stock 18.41 2026-08-17 4 M 0 20000 18.41 D 2028-02-14 Common Stock 20000 181552 D Option to Purchase Common Stock 18.41 2026-08-18 4 M 0 20000 18.41 D 2028-02-14 Common Stock 20000 161552 D Option to Purchase Common Stock 18.41 2026-08-19 4 M 0 20000 18.41 D 2028-02-14 Common Stock 20000 141552 D The options exercised and sales reported on this Form 4 were made pursuant to a written trading plan adopted by the Reporting Person on December 3, 2025 in accordance with Rule 10b5-1. The sales of common shares reported on this Form 4 represent shares that were acquired following exercise of stock options with a ten-year term expiring in February 2028. Represents a weighted average sales price per share. The shares were sold at prices ranging from $98.580 to $99.210. The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $99.980 to $100.780. The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $101.140 to $102.120. The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $102.140 to $103.050. The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $103.160 to $104.010. The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $102.550 to $103.540. The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $103.570 to $104.550. The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $104.585 to $105.080 The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $105.69 to $106.680 The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $106.69 to $107.680 The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Represents a weighted average sales price per share. The shares were sold at prices ranging from $107.69 to $107.900 The Reporting Person has provided to the issuer, and will provide to any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range. Grant to Reporting Person of options, exercisable over a 4-year period measured from the date of grant, 25% after 12 months, then 1/48th of the Option Shares per month thereafter. The date of grant was February 14, 2018. /s/ James R. Oehler, Attorney-in-Fact 2026-08-19