ClearSign Technologies Corp

We incorporate herein by reference the risk factors included under “Part I - Item 1A. Risk Factors” of our Annual Report on Form 10-K for the year ended December 31, 2023 which we filed with the SEC on April 1, 2024, and the risk factors included in the reports and other documents we filed with the SEC subsequent to that date. There are no material changes from the risk factors set forth in such prior filings, except as set forth below.

If we do not have sufficient authorized shares, we will be limited in our ability to reserve adequate shares for certain outstanding warrants.

On April 23, 2024, we consummated an underwritten public offering of 4,620,760 shares of our common stock and accompanying redeemable warrants to purchase up to 4,620,760 shares of common stock, as well as a concurrent private placement of 2,249,763 shares of our common stock, pre-funded warrants to purchase up to 3,155,642 shares of our common stock and redeemable warrants to purchase up to 8,108,106 shares of our common stock (the “Private Warrants”). Pursuant to the terms of the Private Warrants, we are required to reserve and maintain at any time after the initial exercise date thereof, which is October 23, 2024, a sufficient amount of shares issuable upon exercise of the Private Warrants. Based on the authorized but unissued and unreserved shares of common stock as of the date of this report, we may not have sufficient shares available to establish and maintain the required amount for such reserve when required, and we may not be able to issue shares of our common stock upon the exercise of the Private Warrants, which may result in a breach by us of the terms of the Private Warrants. Accordingly, we are asking stockholders to approve an

amendment to our certificate of incorporation to increase the authorized shares of common stock issuable under our certificate of incorporation to 87,500,000 from 62,500,000 shares currently authorized. If the proposal is not approved by the stockholders, based on the authorized but unissued and unreserved shares of common stock as of the date hereof, we may not have sufficient shares available to establish and maintain the required amount for such reserve when required. There are no assurances that stockholder approval will be obtained and in that event we may not be able to issue shares of our common stock upon the exercise of the Private Warrants, which may result in a breach by us of the terms of the Private Warrants. In addition, without the increase to the number of authorized shares of common stock, we will be limited in the amount of equity we may issue in the future.

If we fail to comply with Nasdaq’s continued minimum closing bid requirements by October 29, 2024 or other requirements for continued listing, including stockholder equity requirements, our common stock may be delisted and the price of our common stock and our ability to access the capital markets could be negatively impacted.

Our common stock is listed for trading on Nasdaq, therefore, we must satisfy Nasdaq’s continued listing requirements, including, among other things, a minimum closing bid price requirement of $1.00 per share for 30 consecutive business days. On May 2, 2024, the Nasdaq staff notified us that we did not comply with the minimum $1.00 per share bid price requirement for continued listing, as set forth in Nasdaq Listing Rule 5550(a)(2) during the 30 consecutive business day period beginning on March 20, 2024 and ending on May 1, 2024. We have been granted 180 calendar days, or until October 29, 2024, to regain compliance. In the event that we do not regain compliance within this 180 day period, we may be eligible to seek an additional compliance period of 180 calendar days if we meet certain requirements.

There can be no assurance that we will be able to regain compliance with Nasdaq’s listing rules. If we are unable to regain compliance with the minimum closing bid price requirement or if we fail to meet any of the other continued listing requirements, including stockholder equity requirements, our securities may be delisted from Nasdaq, which could reduce the liquidity of our common stock materially and result in a corresponding material reduction in the price of our common stock. In addition, delisting could harm our ability to raise capital on terms acceptable to us, or at all, and may result in the potential loss of confidence by investors, employees and business development opportunities.