Mountain Lake Acquisition Corp. II

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2025

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:001-43075

Mountain Lake Acquisition Corp. II

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code:(775) 204-1489

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

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 ☒

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 ☒

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 ☐No ☒

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 ☒ No ☐

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.

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.☐

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.☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes☒ No ☐

The registrant’s securities werenot listed on any exchange and had no value as of the last business day of the second fiscal quarter of 2025. The registrant’s Units began trading on the Global Market tier of The Nasdaq Stock Market LLC on January 27, 2026 and the registrant’s Class A Ordinary Shares and Warrants commenced separate trading on March 19, 2026. Accordingly, there was no market value for the registrant’s common equity as of the last business day of the second fiscal quarter of 2025.

As of March 20, 2026, there were 36,980,000 Class A Ordinary Shares, par value $0.0001 per share, and 12,000,000 Class B Ordinary Shares, par value $0.0001 per share, of the registrant issued and outstanding.

Mountain Lake Acquisition Corp. II

FORM 10-K FOR THE FISCAL YEAR ENDED DECEMBER 31, 2025

TABLE OF CONTENTS

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Report (as defined below), including, without limitation, statements under Part II, Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” includes forward-looking statements within the meaning of Section 27A of the Securities Act (as defined below) and Section 21E of the Exchange Act (as defined below). These forward-looking statements can be identified by the use of forward-looking terminology, including the words “believe,” “estimate,” “anticipate,” “expect,” “intend,” “plan,” “may,” “will,” “potential,” “project,” “predict,” “continue,” “should,” “could” or “would” or, in each case, their negative or other variations or comparable terminology. There can be no assurance that actual results will not materially differ from expectations. Such statements include, but are not limited to, any statements relating to our ability to consummate any acquisition or other Business Combination (as defined below) and any other statements that are not statements of current or historical facts. We have based these forward-looking statements on our Management’s (as defined below) current expectations and projections about future events, as well as assumptions made by, and information currently available to our Management, but actual results may differ materially due to various factors, including, but not limited to:

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The forward-looking statements contained in this Report are based on our current expectations and beliefs concerning future developments and their potential effects on us. Future developments affecting us may not be those that we have anticipated. These forward-looking statements involve a number of risks, uncertainties (some of which are beyond our control) or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. Should one or more of these risks or uncertainties materialize, or should any of our assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. We undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required under applicable securities laws.

Unless otherwise stated in this Report, or the context otherwise requires, references to:

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