Rubico Inc. (Nasdaq: RUBI) moves to exit megayacht business

Rhea-AI Filing Summary

Rubico Inc. filed a prospectus supplement relating to the registration of up to 50,000,000 common shares and concurrently reported a plan to exit the megayacht sector.

The company intends to sell its 60-meter, 1,150 gross ton newbuilding megayacht, scheduled for delivery in the second quarter of 2027, either by selling the vessel or the entity holding the shipbuilding contract. Based on independent estimates, management believes a sale could generate €30–35 million (about $34.2–40 million) of gross cash proceeds and eliminate a remaining capital commitment of €26.5 million ($30.2 million). The CEO states that a divestment at current market levels could result in a meaningful equity release, multiple to Rubico’s current market capitalization, and allow capital to be redeployed toward its core tanker business, although completion, terms and use of proceeds remain uncertain.

Positive

• A planned divestment of the megayacht could yield €30–35 million in gross cash proceeds and remove a €26.5 million capital commitment, potentially strengthening Rubico’s balance sheet if completed.

Negative

• None.

Key Figures

Registered common shares: Up to 50,000,000 common shares Estimated megayacht sale proceeds: €30–35 million (about $34.2–40 million) Capital commitment eliminated: €26.5 million ($30.2 million) +3 more

6 metrics

Registered common shares Up to 50,000,000 common shares Prospectus supplement to Form F-1 for Rubico Inc.

Estimated megayacht sale proceeds €30–35 million (about $34.2–40 million) Estimated gross cash proceeds range from divestment of the 60-meter megayacht

Capital commitment eliminated €26.5 million ($30.2 million) Remaining payment prior to megayacht delivery that would be removed by a sale

Megayacht size 60 meters; 1,150 tons gross tonnage Specifications of the newbuilding megayacht scheduled for Q2 2027 delivery

Tanker fleet Two 157,000 dwt Suezmax tankers Core fleet currently owned and operated by Rubico Inc.

MR tanker newbuilding 47,499 dwt, delivery in Q4 2029 Additional tanker on order alongside the megayacht project

Key Terms

megayacht sector, capital commitments, gross tonnage, Suezmax tankers, +1 more

5 terms

megayacht sector market

"decided to divest its interest in its newbuilding megayacht and to exit the megayacht sector"

capital commitments financial

"redeploy capital toward its core business, reduce its future capital commitments, and further simplify"

A capital commitment is a legally binding promise by an investor or limited partner to provide a specified amount of money to a fund, company, or project when the manager requests it. Like a pledged line of credit for a construction job, these commitments matter because they determine future cash that will be called, affect liquidity and planning for both the receiving entity and the pledging investors, and signal how much funding is available for growth or investment over time.

gross tonnage technical

"Megayacht has a length of 60 meters and a gross tonnage of 1,150 tons"

Gross tonnage is a measurement of a ship’s overall size, representing the total volume of its enclosed spaces. It is calculated based on the internal capacity, similar to measuring the total rooms inside a building. This figure helps assess the ship’s size and capacity, which can influence its operating costs, safety standards, and the fees it pays for port services.

Suezmax tankers technical

"owner and operator of two modern, fuel efficient, eco 157,000 dwt Suezmax tankers"

Suezmax tankers are a class of crude oil ships sized to be the largest vessels that can pass through the Suez Canal when fully loaded. Think of them like the biggest truck that can still fit under a low bridge—large enough to carry a lot of oil but constrained by a key route. Investors watch them because their availability and operating costs help set shipping capacity and freight rates, which influence oil prices, energy company margins, and shipping company cash flow.

forward-looking statements regulatory

"Matters discussed in this press release may constitute forward-looking statements"

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.

Offering Details

shelf

Offering

Offering Type shelf

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Available on EDGAR 07/15/2026 - 09:05 AM Accepted by SEC EDGAR 07/15/2026 - 09:03 AM Learn about SEC filing dates

FAQ

What strategic move did Rubico Inc. (RUBI) announce regarding its megayacht project?

Rubico decided to divest its interest in a 60-meter newbuilding megayacht and exit the megayacht sector. It plans to sell either the vessel itself or the entity holding the shipbuilding contract to refocus capital and management resources on its core tanker business.

How much cash could Rubico Inc. (RUBI) raise from selling the megayacht?

Rubico believes a sale of the megayacht could generate €30–35 million in estimated gross cash proceeds, equivalent to about $34.2–40 million. These estimates are based on independent market data and management assumptions and may differ materially from amounts ultimately realized.

What capital commitment will Rubico Inc. (RUBI) avoid if the megayacht is sold?

A sale of the megayacht would eliminate a remaining capital commitment of €26.5 million (about $30.2 million) payable prior to delivery. Management highlights this as a significant future obligation that would be removed if a divestment is successfully completed.

When is Rubico Inc.’s (RUBI) megayacht scheduled to be delivered?

The newbuilding megayacht is scheduled for delivery in the second quarter of 2027. Rubico aims to complete a divestment before that point, but notes there is no assurance regarding the timing, structure, terms, or completion of any transaction.

What assets make up Rubico Inc. (RUBI)’s core tanker business?

Rubico owns and operates two 157,000 dwt Suezmax tankers and has one 47,499 dwt MR tanker newbuilding scheduled for delivery in the fourth quarter of 2029. Management describes this tanker fleet as the company’s core business focus going forward.

Is Rubico Inc. (RUBI) certain to redeploy megayacht sale proceeds into tankers?

Rubico states its intention to redeploy capital toward its core tanker business but has not identified a specific use of proceeds. The company expressly notes there is no assurance it will complete a divestment or redeploy the net proceeds in the tanker sector.

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-295199

Registration No. 333-297277

PROSPECTUS SUPPLEMENT NO. 4

(TO PROSPECTUS DATED MAY 1, 2026)

Up to 50,000,000 Common Shares 

RUBICO INC.

This is a supplement (the “Prospectus Supplement”) to the prospectus, dated May 1, 2026 (as supplemented or amended from time to time, the “Prospectus”) of Rubico Inc. (the “Company”), which forms a part of the Company’s Registration Statement on Form F-1 (Registration Nos. 333-295199 and 333-297277), as amended from time to time.

This Prospectus Supplement is being filed to update and supplement the information included in the Prospectus with the information contained in the Company’s Report on Form 6-K, furnished to the U.S. Securities and Exchange Commission (the “Commission”) on July 15, 2026 (the “Form 6-K”). Accordingly, the Form 6-K is attached to this Prospectus Supplement.

This Prospectus Supplement should be read in conjunction with, and delivered with, the Prospectus and is qualified by reference to the Prospectus except to the extent that the information in this Prospectus Supplement supersedes the information contained in the Prospectus.

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 to it.

Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 10 of the Prospectus for a discussion of information that should be considered in connection with an investment in our securities.

Neither the Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is July 15, 2026.

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 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 July 2026

Commission File Number: 001-42684

Rubico Inc.
(Translation of registrant's name into English)

20 Iouliou Kaisara Str
19002, Paiania
Athens - Greece
(Address of principal executive office)

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 [ X ]      Form 40-F [   ]

On July 15, 2026, the Registrant issued a press release, a copy of which is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

Exhibit 99.1. Press release dated July 15, 2026.

The information contained in this Report, except for the commentary of Kalliopi Ornithopoulou contained in Exhibit 99.1, is hereby incorporated by reference into the Registrant’s registration statement on Form F-3 (File No. 333-297207).

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.

		Rubico Inc.
		(Registrant)
Date: July 15, 2026		/s/ Nikolaos Papastratis
		Nikolaos Papastratis
		Chief Financial Officer

EXHIBIT 99.1

Rubico Announces Its Decision to Exit the Megayacht Sector and Redeploy Capital towards its Core Tanker Business

ATHENS, Greece, July 15, 2026 (GLOBE NEWSWIRE) -- Rubico Inc. (Nasdaq: RUBI) (the “Company” or “Rubico”), a global provider of shipping transportation services specializing in the ownership of vessels, announced today that it has decided to divest its interest in its newbuilding megayacht currently under construction (the “Megayacht”) and to exit the megayacht sector. The Company intends to pursue a sale of the Megayacht, or of the entity that is party to the shipbuilding contract, with the objective of releasing capital for redeployment towards its core tanker business.

The Company believes that focusing on its core tanker business represents the most effective use of its capital and management resources. A divestment of the Megayacht would allow the Company to redeploy capital toward its core business, reduce its future capital commitments, and further simplify its asset base.

The Megayacht has a length of 60 meters and a gross tonnage of 1,150 tons and is scheduled for delivery in the second quarter of 2027. Based on independent market estimates obtained by the Company, for comparable newbuilding megayachts of this size, the Company believes that a sale could generate estimated gross cash proceeds in the range of €30 to €35 million (about $34.2 to $40 million). Further, the sale would eliminate a capital commitment of €26.5 million ($30.2 million) payable prior to delivery of the Megayacht.

There can be no assurance that a divestment will be completed, or as to its timing, structure, terms or the proceeds ultimately realized. The Company has not identified a specific use of proceeds of the sale of the Megayacht and there can be no assurance that the Company will redeploy the net proceeds in the tanker sector. Any transaction would be subject to the negotiation and execution of definitive agreements, the consent of relevant counterparties and financiers, and customary conditions. The estimated valuations set forth above are based on third-party market data and management assumptions and may differ materially from amounts ultimately realized. U.S. dollar amounts in this release are provided for convenience only and are translated at an exchange rate of €1.00 = $1.14 as of July 14, 2026; actual amounts realized may differ.

Kalliopi Ornithopoulou, the Company’s President, Chairwoman & Chief Executive Officer, stated:

“Our decision to exit the megayacht sector reflects our intention to redeploy capital towards our core tanker business. We believe a divestment at current market levels would result in a meaningful equity release, multiple to the Company’s current market cap, while at the same time eliminating a significant  capital commitment.”

About the Company

Rubico Inc. is a global provider of shipping transportation services specializing in the ownership of vessels. The Company is an international owner and operator of two modern, fuel efficient, eco 157,000 dwt Suezmax tankers. Furthermore, the Company owns one 47,499 dwt MR tanker newbuilding scheduled for delivery in the fourth quarter of 2029 and a 60 meter newbuilding megayacht scheduled for delivery in the second quarter of 2027, which the Company intends to divest as described above.

The Company is incorporated under the laws of the Republic of the Marshall Islands and has executive offices in Athens, Greece. The Company’s common shares trade on the Nasdaq Capital Market under the symbol “RUBI”.

Please visit the Company’s website at: https://rubicoinc.com/

For further information please contact:

Nikolaos Papastratis
Chief Financial Officer
Rubico Inc.
Tel: +30 210 812 8107
Email: npapastratis@rubicoinc.com

Forward-Looking Statements

Matters discussed in this press release may constitute forward-looking statements. The Private Securities Litigation Reform Act of 1995 provides safe harbor protections for forward-looking statements in order to encourage companies to provide prospective information about their business. Forward-looking statements include statements concerning plans, objectives, goals, strategies, future events or performance, and underlying assumptions and other statements, which are other than statements of historical facts, including statements regarding the intended divestment of the Company’s megayacht, the estimated market value of such megayacht, the estimated proceeds and potential equity release that may be realized in connection with a divestment, and the redeployment of capital.

The Company desires to take advantage of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 and is including this cautionary statement in connection with this safe harbor legislation. The words “believe,” “anticipate,” “intends,” “estimate,” “forecast,” “project,” “plan,” “potential,” “may,” “should,” “expect” “pending” and similar expressions identify forward-looking statements. The forward-looking statements in this press release are based upon various assumptions, many of which are based, in turn, upon further assumptions, including without limitation, our management’s examination of historical operating trends, data contained in our records and other data available from third parties. Although we believe that these assumptions were reasonable when made, because these assumptions are inherently subject to significant uncertainties and contingencies which are difficult or impossible to predict and are beyond our control, we cannot assure you that we will achieve or accomplish these expectations, beliefs or projections. Please see the Company’s filings with the Securities and Exchange Commission for a more complete discussion of these and other risks and uncertainties. The information set forth herein speaks only as of the date hereof, and the Company disclaims any intention or obligation to update any forward-looking statements as a result of developments occurring after the date of this communication.