X0609 4 2026-08-04 0 0001576280 Guardant Health, Inc. GH 0001336504 CLARK IAN T false 3100 HANOVER STREET PALO ALTO CA 94304 1 0 0 0 0 Common Stock 2026-08-04 4 M 0 2255 91.11 A 10322 I By The Thornton-Clark Family Trust, J Thornton-Clark & I Clark TTE Account Common Stock 2026-08-04 4 M 0 6833 50.57 A 17155 I By The Thornton-Clark Family Trust, J Thornton-Clark & I Clark TTE Account Common Stock 2026-08-04 4 S 0 9088 158.9816 D 8067 I By The Thornton-Clark Family Trust, J Thornton-Clark & I Clark TTE Account Common Stock 2026-08-04 4 S 0 5092 158.8032 D 2975 I By The Thornton-Clark Family Trust, J Thornton-Clark & I Clark TTE Account Stock Option (Right to Buy) 91.11 2026-08-04 4 M 0 2255 0 D 2029-06-18 Common Stock 2255 0 D Stock Option (Right to Buy) 50.57 2026-08-04 4 M 0 6833 0 D 2035-06-18 Common Stock 6833 0 D Represents the weighted average sales price per share. These shares were sold in multiple transactions at prices ranging from $158.510 to $159.435. 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 $158.51 to $159.14. 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. The stock option vested in full on June 12, 2020. The stock option vested in full on June 17, 2026. /s/ John G. Saia, as attorney-in-fact for Ian T. Clark 2026-08-05