Table of Contents Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock CLIR The Nasdaq Stock Market LLC UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 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, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ______________ to _ ...

ClearSign Technologies Corporation (NASDAQ:CLIR) Q3 2021 Earnings Conference Call November 23, 2021 5:00 PM ET Company Participants Matthew Selinger - Firm IR Group Jim Deller - President and Chief Executive Officer Brent Hinds - Vice President of Finance and Controller Conference Call Participants Amit Dayal - H.C. Wainright Operator Good day, and welcome to the ClearSign Technologies Third Quarter 2021 Conference Call. [Operator Instructions] Please note this event is being recorded. I would now like to ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 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 001-35521 CLEARSIGN TECHNOLOGIES CORPORATION (Exact name of registrant as speci ...

ClearSign Technologies Corporation (NASDAQ:CLIR) Q2 2021 Earnings Conference Call September 8, 2021 5:00 PM ET Company Participants Matthew Selinger - Firm IR Group Jim Deller - President and CEO Conference Call Participants Amit Dayal - H.C. Wainwright Robert Kecseg - Las Colinas Capital Management Operator Good day, and welcome to the ClearSign Technologies Second Quarter 2021 Conference Call. All participants will be in listen-only mode. [Operator Instructions]. After today's presentation, there will be ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 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 001-35521 CLEARSIGN TECHNOLOGIES CORPORATION (Exact name of registrant as specified ...

ClearSign Technologies Corporation (NASDAQ:CLIR) Q1 2021 Earnings Conference Call June 15, 2021 5:00 PM ET Company Participants Matthew Selinger - Firm IR Group Jim Deller - President and CEO Brian Fike - Chief Financial Officer Conference Call Participants Amit Dayal - H.C. Wainwright Robert Kecseg - Las Colinas Capital Management Operator Good day, and welcome to the ClearSign Technologies First Quarter 2021 Conference Call. All participants will be in listen-only mode. [Operator Instructions] After today ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 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 001-35521 CLEARSIGN TECHNOLOGIES CORPORATION (Exact name of registrant as specified in its charter) W ...

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 001-35521 CLEARSIGN TECHNOLOGIES CORPORATION (Exact name of registrant as specified in its charter) WASHIN ...

ClearSign Technologies Corporation. (NASDAQ:CLIR) Q4 2020 Results Earnings Conference Call March 23, 2021 5:00 PM ET Company Participants Matthew Selinger - Investor Relations Jim Deller - President and Chief Executive Officer Brian Fike - Chief Financial Officer Conference Call Participants Amit Dayal - H.C. Wainwright Robert Sussman - Bentley Capital Management Jim Kennedy - Marathon Capital Robert Kecseg - Las Colinas Capital Management Operator Good day, and welcome to the ClearSign Technologies Fourth ...

ClearSign Technologies Corporation (NASDAQ:CLIR) Q3 2020 Earnings Conference Call November 19, 2020 5:00 PM ET Company Participants Matthew Selinger - Investor Relations Jim Deller - President and Chief Executive Officer Brian Fike - Chief Financial Officer Conference Call Participants Amit Dayal - H.C. Wainwright Robert Kecseg - Las Colinas Capital Management Operator Good afternoon, and welcome to the ClearSign Technologies Third Quarter Conference Call. All participants will be in listen only mode [Opera ...