SEC Form 424B3 filed by SunPower Inc.

SUNPOWER INC.

Up to 48,521,163 Shares of Common Stock

This prospectus supplement supplements the prospectus dated January 23, 2026 (as amended or supplemented, the “prospectus”), which forms a part of our registration statement on Form S-1 (No. 333-292713). This prospectus supplement is being filed to update and supplement the information in the prospectus with the information contained in our Current Report on Form 8-K filed with the Securities and Exchange Commission on February 2, 2026 (the “Current Report”). Accordingly, we have attached the Current Report to this prospectus supplement.

The prospectus and this prospectus supplement relate to the potential offer and sale of up to 48,521,163 shares of our common stock, par value $0.0001 per share (the “common stock”), by White Lion Capital, LLC (“White Lion” or the “Selling Securityholder”).

The shares of common stock to which the prospectus and this prospectus supplement relate may be issued to White Lion pursuant to the Common Stock Purchase Agreement dated July 16, 2024 between us and White Lion, as amended by Amendment No. 1 to the Common Stock Purchase Agreement dated July 24, 2024, Amendment No. 2 to the Common Stock Purchase Agreement dated August 14, 2024, and Amendment No. 3 to the Common Stock Purchase Agreement dated January 11, 2026 (as amended, the “White Lion Purchase Agreement”), establishing an equity line of credit. Such shares of our common stock include up to 48,521,163 shares of common stock that we may elect, in our sole discretion, to issue and sell to White Lion from time to time during the commitment period under the White Lion Purchase Agreement. See “The White Lion Transaction” and “Selling Securityholder” in the prospectus for more information regarding the White Lion Purchase Agreement and the Selling Securityholder.

The actual number of shares of our common stock issuable to White Lion will vary depending on the then-current market price of shares of our common stock sold to the Selling Securityholder under the White Lion Purchase Agreement and are subject to the further limitations set forth in the White Lion Purchase Agreement.

We are not selling any securities under the prospectus or this prospectus supplement and will not receive any of the proceeds from the sale of shares of common stock by the Selling Securityholder. However, we may receive proceeds of up to approximately $48.5 million from the sale of our common stock to the Selling Securityholder pursuant to the White Lion Purchase Agreement after the date of the prospectus (assuming the shares are sold at a price of $1.00 per share). The actual proceeds from White Lion under the White Lion Purchase Agreement may be less than this amount depending on the number of shares of our common stock sold and the price at which the shares of our common stock are sold.

The Selling Securityholder may sell or otherwise dispose of the shares of common stock described in the prospectus in a number of different ways and at varying prices. See “Plan of Distribution” in the prospectus for more information about how the Selling Securityholder may sell or otherwise dispose of the shares of common stock being registered pursuant to the prospectus. The Selling Securityholder is an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act of 1933, as amended.

The Selling Securityholder will pay all brokerage fees and commissions and similar expenses attributable to the sales of common stock by it. We will pay the expenses (except brokerage fees and commissions and similar expenses) incurred in registering the shares of common stock offered by the prospectus, including legal and accounting fees. See “Plan of Distribution” in the prospectus.

Our common stock and our public warrants are listed on The Nasdaq Stock Market under the symbols “SPWR” and “SPWRW,” respectively. On January 30, 2026, the last reported sales price of our common stock was $1.72 per share, and the last reported sales price of our public warrants was $0.2811 per public warrant.

This prospectus supplement should be read in conjunction with the prospectus, including any amendments or supplements thereto, which is to be delivered with this prospectus supplement. This prospectus supplement is qualified by reference to the prospectus, including any amendments or supplements thereto, except to the extent that the information in this prospectus supplement updates and supersedes the information contained therein.

This prospectus supplement is not complete without, and may not be delivered or utilized except in connection with, the prospectus, including any amendments or supplements thereto.

We are an “emerging growth company” as defined under U.S. federal securities laws and, as such, have elected to comply with reduced public company reporting requirements. The prospectus and this prospectus supplement comply with the requirements that apply to an issuer that is an emerging growth company.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described in the section titled “Risk Factors” beginning on page 8 of the prospectus, and under similar headings in any amendments or supplements to the prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or passed upon the accuracy or adequacy of the prospectus or this prospectus supplement. Any representation to the contrary is a criminal offense.

Prospectus Supplement dated February 2, 2026

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 30, 2026

SUNPOWER INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (510) 270-2507

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

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. ☒

Item 1.01. Entry into a Material Definitive Agreement.

On January 30, 2026, SunPower Inc., a Delaware corporation (the “Company”), entered into a Share Purchase Agreement (the “Share Purchase Agreement”) with Cobalt Power Systems, Inc., a California corporation (“Cobalt”), and Cobalt’s stockholders (the “Stockholders”).

The Company, Cobalt and the Stockholders completed the closing under the Share Purchase Agreement (the “Closing”) on February 2, 2026. At the Closing, the Company acquired all of the outstanding stock of Cobalt from the Stockholders for: (a) 1.8 million shares (the “Closing Consideration Shares”) of common stock of the Company, $0.0001 par value per share (the “Common Stock”), issued at the Closing to the Stockholders; and (b) the agreement to issue an additional $3.33 million of shares of Common Stock on the 12-month anniversary of the Closing and an additional $3.33 million of shares of Common Stock on the 18-month anniversary of the Closing (such additional shares of Common Stock, the “Post-Closing Consideration Shares”). Additionally, the Company agreed to issue up to $2 million of restricted stock units to those Cobalt employees who continue their employment with the Company following the Closing, and 850,000 restricted stock units will be issued as inducement grants to certain Cobalt key employees.

The actual number of Post-Closing Consideration Shares issuable by the Company on the 12- and 18-month anniversaries of the Closing will be determined based on the five-day trailing volume-weighted average price of the Common Stock after market close on the business day immediately prior to the issuance date of the applicable shares. Additionally, the number of Post-Closing Consideration Shares issuable by the Company is subject to adjustment pursuant to customary working capital and balance sheet adjustment terms and subject to offset for certain indemnifiable damages in accordance with the Share Purchase Agreement. Pursuant to the terms and conditions of the Share Purchase Agreement, the Company agreed to register the Closing Consideration Shares and the Post-Closing Consideration Shares for resale to the public under the Securities Act of 1933, as amended (the “Securities Act”), with the initial registration statement to be filed no later than 20 calendar days after the date on which the Company files its Annual Report on Form 10-K for the 2025 fiscal year.

The Share Purchase Agreement includes customary representations and warranties, covenants, and indemnities, in each case under the circumstances and subject to certain limitations set forth in the Share Purchase Agreement. The indemnification obligations under the Share Purchase Agreement are subject to customary deductibles and caps. The Company’s primary source of recovery for indemnifiable damages is set off of such damages against the Post-Closing Consideration Shares issuable by the Company following Closing.

The foregoing summary of the Share Purchase Agreement is not complete, and it is qualified in its entirety by reference to the full text of the Share Purchase Agreement, the form of which is filed as Exhibit 10.1 to this Current Report on Form 8-K and incorporated herein by reference.

Item 2.01. Completion of Acquisition or Disposition of Assets.

The information set forth under Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference.

Item 3.02. Unregistered Sales of Equity Securities.

The information set forth under Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference.

The Closing Consideration Shares issued pursuant to the Share Purchase Agreement, and the Post-Closing Consideration Shares to be issued pursuant to the Share Purchase Agreement, will be issued to the Stockholders in a transaction exempt from registration under the Securities Act in reliance upon the exemption from registration provided by Section 4(a)(2) under the Securities Act.

This Current Report on Form 8-K shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall such securities be offered or sold in the United States absent registration or an applicable exemption from the registration requirements and certificates evidencing such shares contain a legend stating the same. The Closing Consideration Shares and the Post-Closing Consideration Shares have not been registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

3