X0508 4 2025-12-08 0 0001576280 Guardant Health, Inc. GH 0001753159 Talasaz AmirAli 3100 HANOVER STREET PALO ALTO CA 94304 1 1 0 0 Co-Chief Executive Officer 0 Common Stock 2025-12-08 5 J 0 E 387946 0 D 82854 I Shares held by Talasaz Investments, L.P. Common Stock 2025-12-08 5 J 0 E 193973 0 A 218223 I Shares held by AmirAli Talasaz 2018 Children's Remainder Trust, Dated 9/25/2018 Common Stock 2025-12-08 5 J 0 E 193973 0 A 218223 I Shares held by Maryam Eskandari 2018 Children's Remainder Trust, Dated 9/25/2018 Common Stock 2025-12-08 4 S 0 15000 104.2083 D 203223 I Shares held by AmirAli Talasaz 2018 Children's Remainder Trust, Dated 9/25/2018 Common Stock 2025-12-08 4 S 0 30760 105.3372 D 172463 I Shares held by AmirAli Talasaz 2018 Children's Remainder Trust, Dated 9/25/2018 Common Stock 2025-12-08 4 S 0 4240 106 D 168223 I Shares held by AmirAli Talasaz 2018 Children's Remainder Trust, Dated 9/25/2018 Common Stock 2025-12-08 4 S 0 15000 104.2083 D 203223 I Shares held by Maryam Eskandari 2018 Children's Remainder Trust, Dated 9/25/2018 Common Stock 2025-12-08 4 S 0 30760 105.3372 D 172463 I Shares held by Maryam Eskandari 2018 Children's Remainder Trust, Dated 9/25/2018 Common Stock 2025-12-08 4 S 0 4240 106 D 168223 I Shares held by Maryam Eskandari 2018 Children's Remainder Trust, Dated 9/25/2018 Reflects changes in form of ownership from Talasaz Investments LP due to the transfer of shares to The AmirAli Talasaz 2018 Children's Remainder Trust dated 9/25/2018, and Maryam Eskandari 2018 Children's Remainder Trust, dated 9/25/2018. Represents the weighted average sales price per share. These shares were sold in multiple transactions at prices ranging from $104.00 to $104.75. The Reporting Person has provided to the Issuer, and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range. Represents the weighted average sales price per share. These shares were sold in multiple transactions at prices ranging from $105.00 to $105.81. The Reporting Person has provided to the Issuer, and undertakes to provide to the staff of the Securities and Exchange Commission or any security holder of the Issuer, upon request, full information regarding the number of shares sold at each separate price within the range. /s/ John G. Saia, as attorney-in-fact for AmirAli Talasaz 2025-12-10