Page 1

Table of Contents ( Mark One ) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 Delaware ( State or other jurisdiction of incorporation or organization ) Or TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from 4453 North First Street Suite 100 Form 10 - K San Jose , California ( Address of principal executive offices ) For the fiscal year ended December 31 , 2020 Title of Each Class Common Stock , $ .001 Par Value to Commission file number : 000-22339 RAMBUS INC . ( Exact name of registrant as specified in its charter ) Registrant's telephone number , including area code : ( 408 ) 462-8000 Securities registered pursuant to Section 12 ( b ) of the Act : ( I.R.S. Employer Identification No. ) RMBS 94-3112828 Trading Symbol ( s ) Name of Each Exchange on Which Registered The NASDAQ Stock Market LLC ( The NASDAQ Global Select Market ) Securities registered pursuant to Section 12 ( g ) of the Act : None 95134 ( Zip Code ) 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 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 No