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Table of Contents ( 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 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K 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 : 001-33155 Delaware ( State or other jurisdiction of incorporation or organization ) 50 Old Webster Road , Oxford , Massachusetts ( Address of principal executive offices ) IPG PHOTONICS CORPORATION ( Exact name of registrant as specified in its charter ) Title of Class Common Stock , Par Value $ 0.0001 per share Large accelerated filer Non - accelerated filer G ✔ PHOTONICS Registrant's telephone number , including area code : ( 508 ) 373-1100 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol IPGP 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 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 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 ✔ No 04-3444218 ( IRS Employer Identification No. ) 01540 ( Zip Code ) Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company or emerging growth company . See definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Name of Exchange on Which Registered The Nasdaq Stock Market LLC Accelerated filer Smaller reporting company Emerging growth company 000 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 registrant's common stock held by non - affiliates of the registrant was approximately $ 5.7 billion , calculated based upon the closing price as reported by the Nasdaq Global Select Market on June 30 , 2020. For purposes of this disclosure , shares of common stock held by persons who own 5 % or more of the outstanding common stock and shares of common stock held by each officer and director have been excluded in that such persons may be deemed to be " affiliates " as that term is defined under the Rules and Regulations of the Exchange Act . This determination of affiliate status is not necessarily conclusive . As of February 19 , 2021 , 53,533,592 shares of the registrant's common stock were outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant's Proxy Statement for its 2021 Annual Meeting of Stockholders to be filed pursuant to Regulation 14A within 120 days of the end of the registrant's fiscal year ended December 31 , 2020 are incorporated by reference into Part III of this Annual Report on Form 10 - K to the extent stated herein .