UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

REPORT PURSUANT TO
SECTION 13 OR 15(d)
OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): June 11, 2026

Avalanche Treasury Corporation

(Exact name of registrant as specified in its charter)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation 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 x

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. ¨

On June 11, 2026, Avalanche Treasury Corporation (the “Company” or “AVAT”) issued a press release, announcing the closing of the previously announced business combination (the “Business Combination”) pursuant to the business combination agreement, dated as of October 1, 2025 (as amended on January 13, 2026 and on March 17, 2026) by and among Mountain Lake Acquisition Corp., a Cayman Islands exempted company (“MLAC”), the Company, Avalanche SPAC Merger Sub LLC, a Delaware limited liability company, Avalanche Company Merger Sub LLC, a Delaware limited liability company and Avalanche Treasury Company, LLC, a Delaware limited liability company. A copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference.

The information, including Exhibit 99.1, in this Current Report on Form 8-K is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section. The information in this Form 8-K shall not be deemed to be incorporated by reference into any filing under the Securities Act of 1933, as amended, regardless of any general incorporation language in such filings, except as shall otherwise be expressly set forth by specific reference in such filing.

Cautionary Note Regarding Forward-Looking Statements

This Current Report on Form 8-K contains certain forward-looking statements within the meaning of the U.S. federal securities laws, including expectations, intentions, plans, prospects regarding AVAT and the Business Combination and the related private placement (the “Company Unit Subscription” and, together with the Business Combination, the “Transactions”) and statements regarding the anticipated commencement of trading on the Nasdaq Capital Market and AVAT’s vision and business strategy. These forward-looking statements are generally are identified by the words “believe,” “project,” “expect,” “anticipate,” “estimate,” “intend,” “strategy,” “future,” “opportunity,” “potential,” “plan,” “may,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” and similar expressions. Forward-looking statements are predictions, projections and other statements about future events or conditions that are based on current expectations and assumptions and, as a result, are subject to risks and uncertainties. Many factors could cause actual future events to differ materially from the forward-looking statements in this press release, including, but not limited to, the failure of AVAT to maintain the listing of its shares of Class A common stock; costs related to the Transactions and as a result of becoming a public company; changes in business, market, financial, political and regulatory conditions; risks relating to AVAT’s anticipated operations and business; the risk that the anticipated benefits of the Business Combination may not be realized, the highly volatile nature of the price of AVAX; risks related to increased competition in the industries in which AVAT will operate; risks relating to significant legal, commercial, regulatory and technical uncertainty regarding AVAX; risks relating to the treatment of crypto assets for U.S. and foreign tax purposes; risks that AVAT experiences difficulties managing its growth and expanding operations; challenges in implementing Pubco’s business plan, including AVAX-related advisory services and other AVAX-related services, due to operational challenges, significant competition and regulation; the outcome of any potential legal proceedings that may be instituted against AVAT or others following the closing of the Business Combination, and other risks and uncertainties described in the filings of MLAC and AVAT with the Securities and Exchange Commission (the “SEC”). The inclusion of any statement in this press release does not constitute an admission by AVAT or any other person that the events or circumstances described in such statement are material.

The foregoing list of risk factors is not exhaustive. You should carefully consider the foregoing factors and the other risks and uncertainties described in the “Risk Factors” section of the definitive proxy statement of MLAC and final prospectus of AVAT, each dated as of May 14, 2026 and as further supplemented, and other documents that have been filed by MLAC and AVAT with the SEC and other documents to be filed by AVAT from time to time with the SEC. These filings do or will identify and address other important risks and uncertainties that could cause actual events and results to differ materially from those contained in the forward-looking statements. There may be additional risks that AVAT does not presently know or that AVAT currently believes are immaterial that could also cause actual results to differ from those contained in the forward-looking statements.

Forward-looking statements speak only as of the date they are made. Readers are cautioned not to put undue reliance on forward-looking statements, and AVAT assumes no obligation and does not intend to update or revise these forward-looking statements, whether as a result of new information, future events, or otherwise. AVAT does not give any assurance that either it will achieve its expectations. The inclusion of any statement in this press release does not constitute an admission by AVAT or any other person that the events or circumstances described in such statement are material.

(d) Exhibits.

SIGNATURE

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.

Exhibit 99.1

Avalanche Treasury Co. Lists on Nasdaq With Differentiated Approach to Ecosystem Investment

AVAT provides publicly listed exposure to the full Avalanche value chain as institutional blockchain infrastructure adoption rises

NEW YORK, NY – Avalanche Treasury Co. (Nasdaq: AVAT), an operating company and digital asset treasury that allocates capital across the Avalanche economy, today announced the commencement of trading on the Nasdaq Stock Market. Launched in 2020 and purpose-built for enterprise, the Avalanche blockchain combines speed, compliance capabilities, and interoperability.

AVAT was created to accelerate the adoption and growth of Avalanche and open an opportunity for investors to participate in the fundamental infrastructure shift toward blockchain. As a publicly listed operating company, AVAT has no redemption pressure or forced liquidation like typical funds, which we believe can allow the company to reinvest gains, build exposure across the Avalanche ecosystem, and hold its positions through market cycles.

“AVAT intends to deploy capital deliberately to compound Avalanche’s ecosystem value over time, much like a corporate treasury,” said Bart Smith, Chief Executive Officer of Avalanche Treasury Co. “It is not a bet on price. We believe it is an investment into Avalanche that represents meaningful potential for the repositioning of institutional finance. Our Nasdaq listing is designed to provide greater access to this infrastructure shift at the ground level.”

“Avalanche was built from the start with institutional requirements in mind: speed, compliance, interoperability,” said Emin Gün Sirer, Founder and Chief Executive Officer of Ava Labs. “Capital that is committed to compounding value across that ecosystem over the long term is exactly the kind of participation that strengthens the entire network.”

Today, over 550 projects are building on Avalanche, with more than $604 million in institutional funds deployed and over $1.3 billion in real-world assets tokenized on the network. Leading enterprises, financial institutions, and governments are selecting Avalanche as their blockchain of choice, shifting hard-to-move infrastructure on-chain and committing for the long term.

“We believe the next phase of institutional adoption will be driven by structured vehicles that put capital to work inside the ecosystems that matter,” said Rob Hadick, General Partner at Dragonfly. “Avalanche has earned its place as an enterprise blockchain of choice, and we believe a publicly listed treasury vehicle gives institutions the entry point they’ve been waiting for. AVAT offers regulated, structured access to blockchain infrastructure that is aiming to rewire global finance.”

Avalanche Treasury Co. is led by Chief Executive Officer Bart Smith and Chief Operating Officer Laine Litman, two executives who bring a rare combination of institutional finance depth and digital asset expertise. Smith spent over two decades at Susquehanna and AllianceBernstein, building some of the earliest institutional digital asset capabilities on Wall Street. Litman scaled Hidden Road Partners through its acquisition by Ripple and held senior roles at Virtu Financial, Goldman Sachs, Bank of America Merrill Lynch, and UBS.

AVAT is further supported by a board and advisory group that includes Ava Labs founder Emin Gün Sirer, Ava Labs Chief Business Offcer John Nahas, Dragonfly General Partner Rob Hadick, Dragonfly Managing Partner Haseeb Qureshi, Blockworks CEO Jason Yanowitz, and Aave founder Stani Kulechov. Institutional backing comes from Dragonfly, ParaFi Capital, VanEck, Emin Gün Sirer, FalconX, Monarq, Galaxy Digital, Pantera Capital, CoinFund, IMC, Kraken, Borderless, and Hunting Hill.

About AVAT (Avalanche Treasury Co.)

AVAT (Avalanche Treasury Co.) is a Nasdaq-listed company that provides investors with exposure to the Avalanche ecosystem as businesses move on-chain. Investors in AVAT hold shares in a publicly listed company whose value is tied to Avalanche, the blockchain technology platform of choice for some of the world’s most recognized and trusted institutions. AVAT is designed for those who want access to the blockchain infrastructure that offers flexibility, interoperability, and speed without holding a digital asset directly. For more information, visit avat.com.

About Avalanche

Avalanche is a technology platform built for business. Enterprises, financial institutions, consumer applications, and governments run core infrastructure on Avalanche as it provides reliability, compliance, and speed. Users include BlackRock, Franklin Templeton, Apollo, FIFA, and the state of Wyoming. For more information, visit avax.network.

Forward Looking Statements

This press release contains certain forward-looking statements within the meaning of the U.S. federal securities laws, including expectations, hopes, beliefs, intentions, plans, prospects, results or strategies regarding AVAT. These forward-looking statements generally are identified by the words “believe,” “project,” “expect,” “anticipate,” “estimate,” “intend,” “strategy,” “future,” “opportunity,” “potential,” “plan,” “may,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” and similar expressions. Forward-looking statements are predictions, projections and other statements about future events and conditions that are based on current expectations and assumptions. Forward-looking statements are predictions, projections and other statements about future events or conditions that are based on current expectations and assumptions and, as a result, are subject to risks and uncertainties. Many of these factors including but not limited to changes in business, market, financial, political and regulatory conditions, risks relating to AVAT’s anticipated operations and business, risks related to AVAT’s ability to raise additional capital, including the highly volatile nature of the price of AVAX, the risk that AVAT’s stock price will be highly correlated to the price of AVAX and the price of AVAX may decrease, risks related to increased competition in the industries in which AVAT will operate, risks relating to significant legal, commercial, regulatory and technical uncertainty regarding AVAX, risks relating to the treatment of crypto assets for U.S. and foreign tax purposes, challenges in implementing its business plan including AVAX-related financial and advisory services, due to operational challenges, significant competition and regulation, the outcome of any potential legal proceedings that may be instituted against AVAT or its affiliates, and those risk factors discussed in documents AVAT has filed, with the SEC.

The inclusion of any statement in this press release does not constitute an admission by AVAT or any other person that the events or circumstances described in such statement are material.

The foregoing list of risk factors is not exhaustive. There may be additional risks that AVAT does not presently know or that AVAT currently believes are immaterial that could also cause actual results to differ from those contained in the forward-looking statements.

Forward-looking statements speak only as of the date they are made. Readers are cautioned not to put undue reliance on forward-looking statements, and AVAT assumes no obligation and does not intend to update or revise these forward-looking statements, whether as a result of new information, future events or otherwise. AVAT does not give any assurance that either it will achieve its expectations. The inclusion of any statement in this press release does not constitute an admission by AVAT or any other person that the events or circumstances described in such statement are material.