Page 1

Table of Contents 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 to Commission file number : 0-25426 וה NATIONAL INSTRUMENTS CORPORATION ( Exact name of registrant as specified in its charter ) Delaware ( State or other jurisdiction of incorporation or organization ) 11500 North MoPac Expressway Austin , Texas ( address of principal executive offices ) Title of Each Class Common Stock , $ 0.01 par value TM 74-1871327 ( I.R.S. Employer Identification Number ) 78759 Registrant's telephone number , including area code : ( 512 ) 683-0100 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) NATI Securities registered pursuant to Section 12 ( g ) of the Act : Preferred Stock Purchase Rights Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes [ x ] 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 [ 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 registran was required to file such reports ) , and has been subject to such requirements for the past 90 days . Yes [ x ] No ( zip code ) Name of each exchange on which registered The NASDAQ Stock Market , LLC 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 [ x ] No 1 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 [ X ] Accelerated filer Non - 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 . Î Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes No [ x ] The aggregate market value of voting and non - voting common equity held by non - affiliates of the registrant at the close of business on June 30 , 2020 , was $ 3,001,133,422 based upon the last sales price reported for such date on the NASDAQ Stock Market . For purposes of this disclosure , shares of Common Stock held by persons who hold more than 5 % of the outstanding shares of Common Stock and shares held by officers and directors of the registrant as of June 30 , 2020 , have been excluded in that such persons may be deemed to be affiliates . This determination is not necessarily conclusive . At the close of business on February 12 , 2021 , the registrant had outstanding 131,607,055 shares of Common Stock . DOCUMENTS INCORPORATED BY REFERENCE Part III incorporates certain information by reference from the definitive proxy statement to be filed by the registrant for its Annual Meeting of Stockholders to be held on May 11 , 2021 ( the " Proxy Statement " ) .