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Table of Content X 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 September 30 , 2021 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 Delaware ( State or other jurisdiction of incorporation or organization ) 4601 Fairfax Drive , Suite 600 Arlington , Virginia ( Address of Principal Executive Offices ) Title of each class Class A common stock , $ 0.00001 par value Fluence Energy , Inc. ( Exact name of registrant as specified in its charter ) For the transition period from to Commission file number 001-40978 Large accelerated filer Non - accelerated filer O X 87-1304612 ( I.R.S. Employer Identification No. ) (833)358-3623 Registrant's telephone number , including area code Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) FLNC 22203 ( Zip Code ) 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 x 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 registrant was required to file such reports ) ; and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes o No X 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 ( §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 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 . Accelerated filer Smaller reporting company Emerging growth company X 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 . O Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes o No Xx As of March 31 , 2021 , the last business day of the registrant's most recently completed second fiscal quarter , the registrant did not have a public float because there was no established public market for the registrant's common stock . As of December 13 , 2021 , the registrant had 54,143,275 shares of Class A common stock outstanding and 117,173,390 shares of Class B - 1 common stock outstanding .