Cayson Acquisition Corp

The extraordinary general meeting (the “Extraordinary General Meeting”) of Cayson Acquisition Corp (“Cayson,” the “Company,” “we,” “us” or “our”), a Cayman Islands exempted company, will be held at 10:00 a.m. Eastern Time, on September 23, 2026, virtually, athttps://www.virtualshareholdermeeting.com/CAPN2026SM2 or at such other time, on such other date and at such other place at which the meeting may be adjourned or postponed.

The sole purposes of the Extraordinary General Meeting is to consider and vote upon, if thought fit, pass and approve the following resolutions:

Each of the proposals is more fully described in this proxy statement. Please take the time to read carefully each of the proposals in this proxy statement before you vote.

The purpose of the Extension Proposal is to allow us more time to complete our business combination while limiting the amount of funds required to be deposited into the trust account to obtain such additional time. The purpose of the Trust Amendment Proposal is to allow us to amend the Trust Agreement to amend the amount of funds to be deposited into the trust account in connection with extending the time to complete an initial business combination as described in the Extension Proposal. The Extension Proposal and Trust Amendment Proposal are conditioned on each other.

As described in the prospectus for our IPO, we had up to 12 months from the closing of the IPO (or until September 23, 2025) to consummate an initial business combination. However, pursuant to the Existing Memorandum and Articles, we had the right to extend the period of time we had to consummate an initial business combination up to three times by an additional three months each (for a total of up to 21 months from the closing of the IPO, or until June 23, 2026), provided that the Insiders, upon five days’ advance notice prior to the applicable deadline, deposited into the trust account $600,000 (or $0.10 per share) for each extension. The Insiders made such deposit for the first three-month extension in September 2025 and for the second three-month extension in December 2025.

On March 18, 2026, we held an extraordinary general meeting virtually, with respect to voting on, among other things, a proposal to extend the date by which we were required to complete an initial business combination on a monthly basis, up to twelve (12) months (or until March 23, 2027) and a proposal to amend the investment management trust agreement, dated September 19, 2024, to allow us to extend the termination date up to twelve times to March 23, 2027 with all twelve extensions comprised of one month each by providing five days’ advance notice to the Trustee and depositing into the Trust Account a payment of $125,000 per extension until March 23, 2027. On each of March 19, 2026, April 22, 2026, May 21, 2026, June 23, 2026, July 22, 2026 and August 26, 2026, $125,000 was deposited into the Trust Account, extending in monthly increments the deadline from March 23, 2026 to September 23, 2026.

As previously disclosed and as discussed in more detail in our public filings, the Company entered into a definitive agreement for its initial business combination with Mango Financial Group Limited. On September 2, 2026, the parties mutually agreed to terminate the definitive agreement. Accordingly, there is not sufficient time to consummate an initial business combination before September 23, 2026. Without the Extension, if we are unable to complete a business combination on or before September 23, 2026 and the Insiders do not agree to deposit $125,000 into the trust account for the next month extension (which they are under no obligation to do), we would be precluded from completing an initial business combination and, among other things, would be required to cease all operations and ultimately liquidate and dissolve the Company. Accordingly, our Board believes that it is advisable and in our best interest of the Company and our shareholders to approve the Extension on the terms described herein. Notwithstanding the foregoing, we may decide to abandon the Extension Proposal at any time and for any reason prior to effectuating the Extension.

In connection with the Extension Proposal, holders of the Company’s ordinary shares, par value $0.0001 per share (“Ordinary Shares”) who purchased their ordinary shares as part of units sold in the IPO (such units the “Public Units” and such Ordinary Shares, the “Public Shares”, the holders thereof the “Public Shareholders”) may elect to redeem their Public Shares for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the account established in connection with the IPO and into which certain amount of the net proceeds of the IPO, together with certain of the proceeds of a private placement of units (the “Private Placement”, such units the “Private Placement Units”, the Private Placement Units collectively with the Public Units the “units”) simultaneously with the closing date of the IPO, was deposited (the “Trust Account”), including interest earned (net of taxes paid or payable), divided by the number of the then outstanding Public Shares, and which election we refer to as an “Election.” An Election can be made regardless of whether such Public Shareholders vote “FOR” or “AGAINST” the Extension Proposal or do not vote at all, or do not instruct their broker or bank how to vote, at the Extraordinary General Meeting. The Public Shareholders may make an Election regardless of whether such Public Shareholders were holders as of the record date for the Extraordinary General Meeting. Public shareholders who do not make the Election would be entitled to have their shares automatically redeemed for cash if we do not complete our initial business combination by the Extended Date.

WE ARE NOT ASKING YOU TO VOTE ON OUR BUSINESS COMBINATION AT THIS TIME. If the Extension Proposal is implemented and you do not elect to redeem your Public Shares now, you will retain the right to vote on an initial business combination when and if it is submitted to shareholders, and the right to redeem your Public Shares into a pro rata portion of the Trust Account in the event a business combination is approved and completed (as long as your election is made in accordance with the Articles prior to the meeting at which the shareholders’ vote is sought) or the Company has not consummated a business combination by the Extended Date. If the Extension Proposal is not approved, we may not be able to consummate our business combination.

We urge you to vote at the Extraordinary General Meeting regarding the proposals.

Based upon the amount in the Trust Account as of August 31, 2026, the most recent practicable date prior to the date of this proxy statement, which was approximately $38.8 million, we anticipate that the per-share price at which Public Shares will be redeemed from cash held in the Trust Account will be approximately $11.22 at the time of the Extraordinary General Meeting.

The withdrawal of funds from the Trust Account in connection with the Election (the “Withdrawal Amount”) will reduce the amount held in the Trust Account following the Election, and the amount remaining in the Trust Account may be only a small fraction of the approximately $38.8 million that was in the Trust Account as of August 31, 2026. In such event, we may need to obtain additional funds to complete an initial business combination, and there can be no assurance that such funds will be available on terms acceptable or at all.

TO DEMAND REDEMPTION, PRIOR TO 5:00 P.M. EASTERN TIME ON SEPTEMBER 21, 2026, TWO BUSINESS DAYS BEFORE THE EXTRAORDINARY GENERAL MEETING, YOU SHOULD ELECT EITHER TO PHYSICALLY TENDER YOUR SHARE CERTIFICATES TO CONTINENTAL STOCK TRANSFER & TRUST COMPANY OR TO DELIVER YOUR SHARES TO THE TRANSFER AGENT ELECTRONICALLY USING DTC’S DWAC (DEPOSIT/WITHDRAWAL AT CUSTODIAN), AS DESCRIBED HEREIN. YOU SHOULD ENSURE THAT YOUR BANK OR BROKER COMPLIES WITH THE REQUIREMENTS IDENTIFIED ELSEWHERE HEREIN.

If the Extension Proposal is not approved and we do not consummate a business combination by September 23, 2026 and our Insiders do not agree to deposit $125,000 into the trust account for the next month extension (which they are under no obligation to do), as contemplated by our IPO prospectus and in accordance with our Articles, we will (i) cease all operations except for the purpose of winding up, (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the Public Shares at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to us to pay our taxes, divided by the number of the then outstanding Public Shares, which redemption will completely extinguish the rights of the Public Shareholders as shareholders (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably possible following such redemption, subject to the approval of our remaining shareholders and our Board, liquidate and dissolve, subject in each case to the Company’s obligations under Cayman Islands law to provide for claims of creditors and to the other requirements of applicable law.

There will be no redemption rights or liquidating distributions with respect to our rights, each of which will automatically convert into one-tenth of one ordinary share upon consummation of a business combination (“rights”), which rights will expire worthless in the event of our winding up. In the event of a liquidation, holders of our Ordinary Shares issued prior to the IPO (the “Founder Shares”, and such Founder Shares collectively with the Public Shares the “ordinary shares” or “shares”), will not receive any monies held in the Trust Account as a result of their ownership of Founder Shares or the Ordinary Shares included in the Private Units (the “Private Shares”).

The Adjournment Proposal, if adopted, will allow our Board to adjourn the Extraordinary General Meeting to a later date or dates if necessary to approve the Extension Proposal and Trust Amendment Proposal.

The approval of each of the Extension Proposal requires a special resolution under the Articles, being a resolution passed by at least two-thirds of the votes cast by the shareholders who, being present in person (including virtually) or by proxy and entitled to vote at the Extraordinary General Meeting, vote at the Extraordinary General Meeting.

The approval of each of the Trust Amendment Proposal and Adjournment Proposal requires an ordinary resolution under the Trust Agreement and the Articles, respectively, being a resolution passed by a simple majority of the votes cast by the shareholders who, being present in person (including virtually) or by proxy and entitled to vote at the Extraordinary General Meeting, vote at the Extraordinary General Meeting.

Our Board has fixed the close of business on September 1, 2026, as the record date for determining the shareholders entitled to receive notice of and vote at the Extraordinary General Meeting and any adjournment or postponement thereof. Only holders of record of the ordinary shares on that date are entitled to have their votes counted at the Extraordinary General Meeting or any adjournment or postponement thereof

This Proxy Statement contains important information about the Extraordinary General Meeting and the proposals. Please read it carefully and vote your shares.

We will pay for the entire cost of soliciting proxies. We have engaged D.F. King & Co., Inc. (the “Proxy Solicitor”), to assist in the solicitation of proxies for the Extraordinary General Meeting. We have agreed to pay the Proxy Solicitor a fee of $10,000. We will also reimburse the Proxy Solicitor for reasonable out-of-pocket expenses and will indemnify the Proxy Solicitor and its affiliates against certain claims, liabilities, losses, damages and expenses. In addition to these mailed proxy materials, our directors and officers may also solicit proxies in person, by telephone or by other means of communication. These parties will not be paid any additional compensation for soliciting proxies. We may also reimburse brokerage firms, banks and other agents for the cost of forwarding proxy materials to beneficial owners.

This Proxy Statement is dated September 8, 2026 and is first being mailed to shareholders on or about that date.