X4 Pharmaceuticals, Inc

14. Common Stock and Preferred Stock

Common Stock—As of December 31, 2025, the Company’s Certificate of Incorporation, as amended and restated, authorizes the Company to issue 500 million shares of common stock, par value $0.001 per share. The voting, dividend, and liquidation rights of the holders of the Company’s common stock are subject to and qualified by the rights, powers and preferences of the holders of any preferred stock that may be issued. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any. No cash dividends have been declared or paid to date.

Preferred Stock—As of December 31, 2025, the Company’s Certificate of Incorporation, as amended, authorizes the Company to issue 10 million shares of $0.001 par value share. As of December 31, 2025 and December 31, 2024, no shares of preferred stock were outstanding.

Reverse Stock Split— On April 17, 2025, the Company’s stockholders approved an amendment to the Certificate of Incorporation to combine outstanding shares of the Company’s common stock into a lesser number of outstanding shares, by a ratio of not less than one-for-fifteen and not more than one-for-thirty and the Board of Directors approved a Reverse Stock Split at a ratio of 30 for one. The Reverse Stock Split was effective on April 28, 2025. As a result of the Reverse Stock Split, every 30 shares of common stock issued or outstanding were automatically reclassified into one validly issued, fully-paid and non-assessable new share of common stock, subject to the treatment of fractional shares, without any action on the part of the holders. Proportional adjustments were made to the number of shares of common stock awarded and available for issuance under the Company’s equity incentive plans, as well as the exercise price and the number of shares issuable upon the exercise or conversion of outstanding stock options and other equity securities. Outstanding warrants were also adjusted in accordance with their terms, which resulted in proportionate adjustments being made to the number of shares issuable upon exercise of such warrants and to the exercise and redemption prices of such warrants. The Reverse Stock Split did not affect the number of authorized shares of common stock or the par value of the common stock. Unless otherwise noted, all references to common stock share and per share amounts in this Annual Report on Form 10-K have been retroactively adjusted to reflect the Reverse Stock Split.

ATM Sales Agreement —The Company is party to a Controlled Equity Offering SMSales Agreement (“ATM”), dated as of August 7, 2020, pursuant to which the Company may offer and sell shares of its common stock through one or more investment banks. For the year ended December 31, 2025 and to date through December 31, 2025, the Company has sold $9.7 million and $24.2 million, respectively, of its common stock, net of offering costs, under the ATM. Pursuant to its Registration Statement on Form S-3 that became effective on August 24, 2023 and the related ATM prospectus contained therein, the Company may offer and sell shares of its common stock having an aggregate offering price of up to an additional $65.3 million.

Purchase Agreement— In June 2025, the Company entered into a common stock purchase agreement (“Purchase Agreement”) with Lincoln Park Capital Fund LLC pursuant to which Lincoln Park committed to purchase, at the Company’s request from time to time over a 24-month period, shares of common stock having an aggregate offering price of up to $40.0 million, subject to certain limitations including a common share cap that will require shareholder approval to exceed (the “Purchase Shares”). In consideration for entering into the Purchase Agreement, the Company issued 137,099 shares of common stock (the “Commitment Shares”) to Lincoln Park as a commitment fee. The fair value of the Commitment Shares, which was consideration given to Lincoln Park in exchange for entering into the agreement and was not significant, was measured on the issuance date as determined based on the closing price of the Company’s common stock. Through August 21, 2025, the Company sold 1,297,936 shares of common stock to Lincoln Park for aggregate proceeds of $2.2 million. The issuance of the Purchase Shares and Commitment Shares were registered pursuant to an effective shelf registration statement on Form S-3 and related base prospectus, as supplemented by a prospectus supplement filed on June 23, 2025. The Company terminated the Purchase Agreement effective August 21, 2025.

Q3 2025 Private Placement— On August 11, 2025 and August 12, 2025, the Company entered into securities purchase agreements pursuant to which the Company sold to several institutional and accredited investors (the “Investors”) in a private placement (the “Q3 2025 Private Placement”),11.0 million shares of common stock at a price of $1.42 per share and pre-funded warrants to purchase 48.9 million shares of common stock at a purchase price of $1.419 per pre-funded warrant (representing the price of $1.42 per share minus the $0.001 per share exercise price of each such prefunded warrant). The pre-funded warrants are exercisable, subject to certain beneficial ownership restrictions, at any time after their original issuance and will not expire. The Q3 2025 Private Placement closed on August 13, 2025. The net proceeds of $81.0 million, after deducting placement agent fees and offering expenses, received for the shares of common stock and the pre-funded warrants was recorded as permanent equity as the Company concluded that the shares of common stock and pre-funded warrants met the criteria for permanent equity classification.

Also, on August 11, 2025 and August 12, 2025, the Company entered into registration rights agreements with the Investors, pursuant to which the Company agreed to register for resale the common shares issued in the Q3 2025 Private Placement and the issuance of the shares of common stock underlying the pre-funded warrants held by the Investors. Such registration statement was filed on September 10, 2025 and was declared effective by the SEC on September 17, 2025. The Company has agreed to use commercially reasonable efforts to keep such registration statement effective until the date the shares of common stock sold in the Q3 2025 Private Placement and the shares of common stock underlying the pre-funded warrants covered by such registration statement have been sold or may be resold pursuant to Rule 144 without restriction.

Q4 Public Offering-— On October 23, 2025, the Company entered into an underwriting agreement with certain underwriters to issue and sell 45.9 million shares of the Company’s common stock at a public offering price of $2.90 per share and, in lieu of common stock to certain investors, pre-funded warrants to purchase 0.7 million shares of the Company’s common stock (the “Pre-Funded Warrants”) at a public offering price of $2.899 per share, which represents the per share public offering price for the common stock less the $0.001 per share exercise price for each Pre-Funded Warrant (the “Q4 Public Offering”). In addition, the Company granted the underwriters an option for a period of 30 days to purchase up to an additional 7.0 million shares of common stock at the public offering price, less the underwriting discounts and commissions, which the underwriters exercised in full on October 24, 2025. The net proceeds of $145.6 million, after deducting placement agent fees and offering expenses, received for the shares of common stock and the Pre-Funded Warrants was recorded as permanent equity as the Company concluded that the shares of common stock and pre-funded warrants met the criteria for permanent equity classification.

The Pre-Funded Warrants are exercisable at any time after the date of issuance. A holder of Pre-Funded Warrants may not exercise the warrant if the holder, together with its affiliates, would beneficially own more than 4.99% or 9.99%, as applicable, of the number of shares of common stock outstanding immediately after giving effect to such exercise. A holder of Pre-Funded Warrants may increase or decrease this percentage to a percentage not in excess of 19.99% by providing prior notice to the Company, provided that any increase will not be effective until the 61st day after such notice is delivered to the Company.