X0508 4 2025-11-26 0 0001159036 HALOZYME THERAPEUTICS, INC. HALO 0001528185 Torley Helen C/O HALOZYME THERAPEUTICS, INC. 12390 EL CAMINO REAL SAN DIEGO CA 92130 1 1 0 0 PRESIDENT AND CEO 1 Common Stock 2025-11-26 4 G 0 25000 0 D 708719 D Common Stock 2025-12-01 4 M 0 16569 8.11 A 725288 D Common Stock 2025-12-01 4 S 0 10406 68.512 D 714882 D Common Stock 2025-12-01 4 S 0 5402 69.441 D 709480 D Common Stock 2025-12-01 4 S 0 500 70.362 D 708980 D Common Stock 2025-12-01 4 S 0 261 71.60 D 708719 D Option to Purchase Common Stock 8.11 2025-12-01 4 M 0 16569 8.11 D 2026-02-03 Common Stock 16569 0 D Represents a bona fide gift to charity. The options exercised and sales reported on this Form 4 were made pursuant to a written trading plan adopted by the Reporting Person on March 21, 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 less than one year in February 2026. Represents a weighted average sales price per share. The shares were sold at prices ranging from $68.100 to $69.080. 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 $69.160 to $70.100. 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 $70.160 to $70.500. 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 3, 2016. /s/ James R. Oehler, Attorney-in-Fact 2025-12-01