X0609 4 2026-10-01 0 0001159036 HALOZYME THERAPEUTICS, INC. HALO 0001543792 Posard Matthew L. false C/O HALOZYME THERAPEUTICS, INC. 12390 EL CAMINO REAL SAN DIEGO CA 92130 1 0 0 0 1 Common Stock 2026-10-01 4 S 0 730 107.168 D 58109 D Common Stock 2026-10-01 4 S 0 3300 108.454 D 54809 D Common Stock 2026-10-01 4 S 0 1100 109.569 D 53709 D Common Stock 2026-10-01 4 S 0 100 110.04 D 53609 D The sales reported on this Form 4 were made pursuant to a written trading plan adopted by the Reporting Person on June 15, 2026 in accordance with Rule 10b5-1. Represents a weighted average sales price per share. The shares were sold at prices ranging from $106.930 to $107.660. 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 $107.990 to $108.930. 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 $109.040 to $109.970. 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. /s/ James R. Oehler, Attorney-in-Fact 2026-10-02