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☑ ☐ UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from Commission file number : 001-38997 to RAPT THERAPEUTICS , INC . ( Exact name of Registrant as specified in its charter ) Delaware ( State or other jurisdiction of incorporation or organization ) 561 Eccles Avenue 47-3313701 ( I.R.S. Employer Identification No. ) South San Francisco , California 94080 ( Address of principal executive offices and zip code ) Registrant's telephone number , including area code : ( 650 ) 489-9000 Securities registered pursuant to Section 12 ( b ) of the Act : Title of Each Class of Securities Registered Common Stock , par value $ 0.0001 per share Trading Symbol RAPT Name of Each Exchange on Which Registered Nasdaq Global Market Securities registered pursuant to Section 12 ( g ) of the Act : None Indicate by check mark if the Registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . YES □ NO Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . 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 NO □ Indicate by check mark whether the Registrant has submitted electronically and posted on its corporate Website , if any , every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S - T during the preceding 12 months ( or for such shorter period that the Registrant was required to submit and post such files ) . YES NO □ Indicate by check mark whether the Registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Large accelerated filer Non - accelerated filer ☐ ☑ Accelerated filer Smaller reporting company Emerging growth company ☐ ☑ If an emerging growth company , indicate by check mark if the Registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Indicate by check mark whether the Registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . YES □ NO The aggregate market value of the common stock held by non - affiliates of the registrant as of June 30 , 2020 ( the last business day of the registrant's most recently completed second fiscal quarter ) was approximately $ 437.0 million , based on the closing price of the registrant's common stock , as reported by the Nasdaq Global Market on June 30 , 2020 of $ 29.02 per share . Shares of the registrant's common stock held by each executive officer , director and holder of 5 % or more of the outstanding common stock have been excluded in that such persons may be deemed to be affiliates . This calculation does not reflect a determination that certain persons are affiliates of the registrant for any other purpose . As of March 4 , 2021 , the number of outstanding shares of the Registrant's common stock , par value $ 0.0001 per share , was 24,866,248 . DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant's Definitive Proxy Statement for the 2021 Annual Meeting of Stockholders to be filed with the U.S. Securities and Exchange Commission pursuant to Regulation 14A within 120 days after the end of the fiscal year covered by this Annual Report on Form 10 - K are incorporated by reference in Part III , Items 10-14 of this Annual Report on Form 10 - K .