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UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON , DC 20549 ( Mark One ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 Act . No □ FORM 10 - K TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR For the transition period from Delaware ( State or other jurisdiction of incorporation or organization ) GUARDANT HEALTH , INC . ( Exact Name of Registrant as Specified in its Charter ) to Commission File Number : 001-38683 Title of each class Common Stock , par value $ 0.00001 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) GH 505 Penobscot Dr. Redwood City , California 94063 ( Address of principal executive offices ) ( Zip Code ) Registrant's telephone number , including area code : ( 855 ) 698-8887 45-4139254 Securities registered pursuant to Section 12 ( g ) of the Act : None ( I.R.S. Employer Identification No. ) Name of each exchange on which registered The Nasdaq Global Select Market Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes 冈 Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Exchange Yes ☐ No " Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes 区 No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( §232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No