Page 1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 Form 10 - K ( Mark One ) X 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 to Commission File Number 001-34899 Pacific Biosciences of California , Inc. ( Exact name of registrant as specified in its charter ) Delaware ( State or other jurisdiction of incorporation or organization ) 1305 O'Brien Drive Menlo Park , CA 94025 ( Address of principal executive offices ) Title of each class Common Stock , par value $ 0.001 per share 0 X ( Registrant's telephone number , including area code ) ( 650 ) 521-8000 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) PACB Securities registered pursuant to Section 12 ( g ) of the Act : None 16-1590339 ( I.R.S. Employer Identification No. ) 94025 ( Zip Code ) Name of each exchange on which registered The NASDAQ Stock Market LLC Yes o Nox Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . 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 o No x 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 x No o 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 and post such files ) . Yes x No o 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 . ( Check one ) : Large accelerated filer Non - accelerated filer Accelerated filer Smaller reporting company Emerging growth company 0 X 0 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 . o 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 . Yes o Nox Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes o No x Aggregate market value of registrant's common stock held by non - affiliates of the registrant on June 30 , 2020 , based upon the closing price of Common Stock on such date as reported by NASDAQ Global Select Market , was approximately $ 498,891,052 . Shares of voting stock held by each officer and director have been excluded in that such persons may be deemed to be affiliates . This assumption regarding affiliate status is not necessarily a conclusive determination for other purposes . Number of shares outstanding of the issuer's common stock as of January 31 , 2021 : 193,102,689 DOCUMENTS INCORPORATED BY REFERENCE : Portions of the registrant's definitive Proxy Statement relating to its 2021 Annual Meeting of Stockholders to be held on June 16 , 2021 are incorporated by reference into Part III of this Annual Report on Form 10 - K where indicated . Such Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates .