X0609 4 2026-10-06 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 2026-10-06 4 M 0 20000 18.41 A 787780 D Common Stock 2026-10-06 4 S 0 2300 107.902 D 785480 D Common Stock 2026-10-06 4 S 0 6000 109.334 D 779480 D Common Stock 2026-10-06 4 S 0 9920 109.891 D 769560 D Common Stock 2026-10-06 4 S 0 1780 110.812 D 767780 D Common Stock 2026-10-07 4 M 0 20000 18.41 A 787780 D Common Stock 2026-10-07 4 S 0 8600 111.031 D 779180 D Common Stock 2026-10-07 4 S 0 10300 111.839 D 768880 D Common Stock 2026-10-07 4 S 0 900 112.78 D 767980 D Common Stock 2026-10-07 4 S 0 200 113.693 D 767780 D Common Stock 2026-10-08 4 M 0 20000 18.41 A 787780 D Common Stock 2026-10-08 4 S 0 4810 108.179 D 782970 D Common Stock 2026-10-08 4 S 0 3090 108.908 D 779880 D Common Stock 2026-10-08 4 S 0 11900 109.995 D 767980 D Common Stock 2026-10-08 4 S 0 200 110.51 D 767780 D Option to Purchase Common Stock 18.41 2026-10-06 4 M 0 20000 18.41 D 2028-02-14 Common Stock 20000 61552 D Option to Purchase Common Stock 18.41 2026-10-07 4 M 0 20000 18.41 D 2028-02-14 Common Stock 20000 41552 D Option to Purchase Common Stock 18.41 2026-10-08 4 M 0 20000 18.41 D 2028-02-14 Common Stock 20000 21552 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 $107.480 to $108.290. 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 $108.530 to $109.520. 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 $109.530 to $110.510. 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 $110.530 to $111.210. 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 $110.360 to $111.350. 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 $111.380 to $112.360. 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 $112.400 to $113.190. 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 $113.590 to $113.860. 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 $107.480 to $108.475. 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 $108.480 to $109.470. 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 $109.510 to $110.500. 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 2026-10-08