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Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , DC 20549 FORM 10 - K ( Mark One ) □ 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 Delaware ( State or other jurisdiction of Incorporation or organization ) Title of Each Class Common Stock Commission File Number 000-23441 POWER INTEGRATIONS , INC . ( Exact name of registrant as specified in its charter ) 5245 Hellyer Avenue San Jose , California ( Address of principal executive offices ) Large Accelerated Filer Non - accelerated Filer ( 408 ) 414-9200 ( Registrant's telephone number , including area code ) Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) 94-3065014 ( I.R.S. Employer Identification No. ) POWI 95138-1002 ( Zip code ) No ® 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 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 Name of Each Exchange on Which Registered The Nasdaq Global Select Market 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 during the preceding 12 months ( or for such shorter period that the registrant was required to submit 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 : 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 registrant's voting and non - voting common stock held by non - affiliates of registrant on June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter , was approximately $ 2.6 billion , based upon the closing sale price of the common stock as reported on The Nasdaq Global Select Market . Shares of common stock held by each officer and director have been excluded in that such persons may be deemed to be affiliates . This determination of affiliate status is not a conclusive determination for other purposes . Outstanding shares of registrant's common stock , $ 0.001 par value , as of February 2 , 2021 : 60,053,859 . DOCUMENTS INCORPORATED BY REFERENCE The information required by Part III of this report , to the extent not set forth herein , is incorporated by reference from the Registrant's definitive proxy statement relating to the 2021 annual meeting of stockholders , which definitive proxy statement will be filed with the Securities and Exchange Commission within 120 days after the fiscal year to which this Report relates .