WISeKey (WKEY) moves WISeSat–Columbus SPAC deal forward with Form F-4

Rhea-AI Filing Summary

WISeKey International Holding Ltd reports that WISeSat.Space Holdings Corp. (“Pubco”), a wholly owned subsidiary of WISeSat.Space Corp., has filed a registration statement on Form F-4 with the SEC for a previously announced business combination with Columbus Acquisition Corp. (“CAC”). The deal is governed by a Business Combination Agreement dated November 9, 2025. Completion of the transaction requires the Form F-4 to be declared effective, approval of CAC shareholders, and Nasdaq approval to list Pubco’s registered shares. If completed, both WISeSat and CAC will become subsidiaries of Pubco, and the combined company is expected to trade on Nasdaq under the ticker symbol “SAIQ”.

Insights

Cross-border M&A and SPAC analyst

WISeKey advances WISeSat SPAC deal but key approvals remain.

WISeSat’s planned combination with Columbus Acquisition Corp moves forward as Pubco files a Form F-4 registration statement. This is a key regulatory step for a SPAC transaction, establishing the framework for shareholder approval and listing of the combined company on Nasdaq as “SAIQ”.

The transaction is still contingent on several conditions, including SEC effectiveness of the Form F-4, approval of CAC shareholders, and Nasdaq listing approval for Pubco’s registered shares. Any delay or failure at these stages could prevent or postpone closing of the combination.

Given these dependencies, the development is administrative rather than final. Subsequent disclosures about SEC effectiveness, shareholder voting outcomes, and Nasdaq’s listing decision will clarify whether the combination proceeds as outlined in the Business Combination Agreement dated November 9, 2025.

Key Figures

Form F-4 filing date: June 23, 2026 Business Combination Agreement date: November 9, 2025 Current SPAC ticker: Nasdaq: COLA +2 more

5 metrics

Form F-4 filing date June 23, 2026 Pubco filed registration statement with SEC

Business Combination Agreement date November 9, 2025 Definitive agreement among WISeSat, CAC, Pubco, WISeKey and Merger Sub

Current SPAC ticker Nasdaq: COLA Ticker symbol for Columbus Acquisition Corp

Expected new ticker SAIQ Planned Nasdaq symbol for combined company after closing

Form type Form 6-K Report of Foreign Private Issuer by WISeKey International Holding Ltd

Key Terms

Form F-4, Business Combination Agreement, special purpose acquisition company, forward-looking statements, +1 more

5 terms

Form F-4 regulatory

"Pubco filed a registration statement on Form F-4 with the U.S. Securities and Exchange Commission"

Form F-4 is an official filing with the U.S. Securities and Exchange Commission used by non-U.S. companies when they offer securities in connection with mergers, acquisitions, exchange offers or similar transactions. It acts like a detailed product label or instruction manual that explains the deal, the securities being offered, financials, risks and voting requirements, and it matters to investors because it provides the essential facts needed to evaluate how the transaction could affect ownership, value and future returns.

Business Combination Agreement financial

"proposed business combination contemplated by a definitive Business Combination Agreement, dated November 9, 2025"

A business combination agreement is a detailed contract that lays out the terms for two companies to join together—covering price, how ownership will be split, the steps needed to close the deal, and what each side promises to do or avoid before closing. For investors it matters because the agreement determines potential changes in value, control, timing, and risk exposure—think of it like the playbook for a merger that shows who wins, who pays, and what could still derail the plan.

special purpose acquisition company financial

"Columbus Acquisition Corp (Nasdaq: COLA) (“CAC”), a special purpose acquisition company"

A special purpose acquisition company (SPAC) is a company formed with the sole purpose of raising money through a public offering to buy or merge with an existing private business. It acts like a vehicle that allows private companies to go public more quickly and with less complexity. For investors, it offers an opportunity to invest early in a potential acquisition, though it also carries risks if the intended deal doesn’t materialize.

forward-looking statements regulatory

"This report contains forward-looking statements within the meaning of applicable securities laws"

Forward-looking statements are predictions or plans that companies share about what they expect to happen in the future, like estimating sales or profits. They matter because they help investors understand a company's outlook, but since they are based on guesses and assumptions, they can sometimes be wrong.

registration statement regulatory

"the Registration Statement relates to the previously announced proposed business combination"

A registration statement is a formal document that companies file with a government agency to offer new shares of stock to the public. It provides essential information about the company's finances, operations, and risks, helping investors make informed decisions. Think of it as a detailed product description that ensures transparency and trust before buying into a company.

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Form 6-K: How Foreign Companies Report to the SEC →

Available on EDGAR 06/26/2026 - 04:16 PM Accepted by SEC EDGAR 06/26/2026 - 04:15 PM Learn about SEC filing dates

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16 under the

Securities Exchange Act of 1934

For the month of June 2026

Commission File Number: 001-39115

WISEKEY INTERNATIONAL HOLDING AG

(Exact Name of Registrant as Specified in Charter)

WISEKEY INTERNATIONAL HOLDING LTD

(Translation of Registrant’s name into English)

Canton of Zug, Switzerland		General-Guisan-Strasse 6 CH-6300 Zug, Switzerland		Not Applicable
(State or other jurisdiction of incorporation or organization)		(Address of principal executive office)		(I.R.S. Employer Identification No.)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

☒ Form 20-F              ☐ Form 40-F

On June 23, 2026, WISeSat.Space Holdings Corp. (“Pubco”) filed a registration statement on Form F-4 (the “Registration Statement”) with the U.S. Securities and Exchange Commission (the “SEC”). Pubco is a wholly-owned subsidiary of WISeSat.Space Corp. (“WISeSat”), which is itself a subsidiary of WISeKey International Holding Ltd (“WISeKey”). As of the date of this report, the Registration Statement has not been declared effective by the SEC.

The Registration Statement relates to the previously announced proposed business combination contemplated by a definitive Business Combination Agreement, dated November 9, 2025 (the “Business Combination Agreement”), by and among WISeSat, Columbus Acquisition Corp (Nasdaq: COLA) (“CAC”), a special purpose acquisition company, Pubco, WISeKey, and WISeSat Merger Sub Corp. Subject to the Registration Statement being declared effective by the SEC, and upon completion of the proposed business combination, each of WISeSat and CAC will become subsidiaries of Pubco. The combined company is expected to trade on Nasdaq under the ticker symbol “SAIQ”.

The completion of the proposed transaction contemplated by the Business Combination Agreement remains subject to certain closing conditions, including the approval of CAC shareholders, the effectiveness of the Registration Statement, and approval of the listing of the registered shares of Pubco by Nasdaq.

No Offer or Solicitation

This communication is for informational purposes only and does not constitute an offer to sell or the solicitation of an offer to buy any securities, or a solicitation of any vote, consent or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. Any offering of securities in connection with the proposed business combination will be made only by means of a prospectus meeting the requirements of applicable law.

Forward-Looking Statements

This report contains forward-looking statements within the meaning of applicable securities laws, including statements regarding the proposed business combination, the SEC review process, any effectiveness of the Registration Statement and the anticipated completion of the proposed business combination. Forward-looking statements are subject to risks, uncertainties and assumptions, many of which are outside the control of Pubco, CAC, WISeSat and WISeKey. Actual results may differ materially from those expressed or implied by these forward-looking statements as a result of a variety of factors, including the risk that the proposed business combination may not be completed in a timely manner or at all, the risk that the Registration Statement may not become effective, the risk that CAC shareholder approval may not be obtained, the risk that other closing conditions may not be satisfied or waived, and other risks and uncertainties described in CAC’s filings with the SEC and described in the Registration Statement. Readers are cautioned not to place undue reliance on forward-looking statements, which speak only as of the date made. The parties undertake no obligation to update or revise any forward-looking statements except as required by applicable law.

1

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, thereunto duly authorized.

Date: June 26, 2026	WISEKEY INTERNATIONAL HOLDING AG
	By:	/s/ Carlos Moreira
	Name:	Carlos Moreira
	Title:	Chief Executive Officer
	By:	/s/ John O’Hara
	Name:	John O’Hara
	Title:	Chief Financial Officer

2

FAQ

What does WISeKey (WKEY) announce about the WISeSat business combination?

WISeKey reports that WISeSat’s subsidiary Pubco has filed a Form F-4 registration statement for a proposed business combination with Columbus Acquisition Corp. The deal would make WISeSat and CAC subsidiaries of Pubco if all conditions and approvals are satisfied.

Which entities are involved in WISeKey (WKEY)’s WISeSat SPAC transaction?

The transaction involves WISeSat.Space Corp., Columbus Acquisition Corp (CAC), WISeSat.Space Holdings Corp. (Pubco), WISeKey International Holding Ltd, and WISeSat Merger Sub Corp. These parties are bound by a Business Combination Agreement dated November 9, 2025, outlining the proposed structure.

What stock ticker will the combined WISeSat and CAC company trade under?

If the proposed business combination closes, the combined company is expected to trade on Nasdaq under the ticker symbol “SAIQ.” This is contingent on SEC effectiveness of the Form F-4, CAC shareholder approval, and Nasdaq approval of Pubco’s registered share listing.

What conditions must be met for WISeKey (WKEY)’s WISeSat business combination to close?

Closing requires the Form F-4 registration statement to be declared effective by the SEC, approval of the transaction by CAC shareholders, and Nasdaq approval to list Pubco’s registered shares. Other closing conditions in the Business Combination Agreement must also be satisfied or waived.

Does WISeKey’s June 2026 update constitute an offer to buy or sell securities?

No. The communication is described as informational only and not an offer to sell or solicitation to buy securities or obtain votes. Any securities offering tied to the business combination would occur solely through a prospectus meeting applicable legal requirements.

What forward-looking risks does WISeKey (WKEY) highlight about the WISeSat deal?

The report warns that the business combination may not close, the Form F-4 may not become effective, CAC shareholder approval may not be obtained, or other closing conditions may fail. It notes that actual outcomes can differ materially from forward-looking statements due to these risks.