L1 Capital reports 1.7% C3is Inc. ownership stake

L1 Capital Global Opportunities Master Fund, Ltd. filed an amended Schedule 13G reporting beneficial ownership of 223,038 shares of C3is Inc. common stock, representing 1.7% of the outstanding class.

Rhea-AI Filing Summary

L1 Capital Global Opportunities Master Fund, Ltd. filed an amended Schedule 13G reporting beneficial ownership of 223,038 shares of C3is Inc. common stock, representing 1.7% of the outstanding class. The ownership consists of Series B-2, Series C-2 and other warrants to purchase common shares, all with sole voting and dispositive power and no shared power. The percentage is based on 13,082,612 C3is common shares outstanding as referenced in a July 28, 2026 prospectus. L1 Capital notes that its directors David Feldman and Joel Arber may be deemed beneficial owners under Rule 13d-3 but each disclaims beneficial ownership except to the extent of any pecuniary interest.

Key Figures

Beneficially owned shares: 223,038 shares Ownership percentage: 1.7% Shares outstanding baseline: 13,082,612 shares +4 more

7 metrics

Beneficially owned shares 223,038 shares Common Stock, $0.01 par value, reported by L1 Capital Global Opportunities Master Fund, Ltd.

Ownership percentage 1.7% Percent of C3is Inc. common stock class beneficially owned by L1 Capital

Shares outstanding baseline 13,082,612 shares C3is Inc. common shares outstanding referenced from July 28, 2026 prospectus

Series B-2 Warrants 97,027 warrants Series B-2 Warrants to purchase C3is Inc. common shares included in beneficial ownership

Series C-2 Warrants 112,617 warrants Series C-2 Warrants to purchase C3is Inc. common shares included in beneficial ownership

Other warrants 13,393 warrants Additional warrants to purchase C3is Inc. common shares included in beneficial ownership

Ownership classification 5 percent or less Item 5 discloses ownership of 5 percent or less of the class

Key Terms

beneficially own, Series B-2 Warrants, Series C-2 Warrants, dispositive power, +2 more

6 terms

beneficially own regulatory

"may be deemed to beneficially own (as that term is defined in Rule 13d-3)"

Beneficially own means having the economic rights and risks of a security—such as the right to receive dividends, sell the shares, or profit from price changes—whether or not your name appears on the official share register. Think of it like renting a car: you use it and reap the benefits even if the title lists someone else. Investors care because beneficial ownership determines who truly controls value, must be disclosed under securities rules, and can signal potential influence or trading activity that affects a stock’s price.

Series B-2 Warrants financial

"97,027 Series B-2 Warrants to purchase Common Shares"

Series C-2 Warrants financial

"112,617 Series C-2 Warrants to purchase Common Shares"

dispositive power financial

"Sole Dispositive Power 223,038.00"

Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.

Rule 13d-3 regulatory

"beneficially own (as that term is defined in Rule 13d-3 )"

Rule 13d-3 defines who is treated as the beneficial owner of a company’s shares for U.S. securities disclosure rules — essentially anyone who has the power to vote or direct how shares are voted, or the power to buy or sell them, even if they don’t hold the certificates. For investors this matters because crossing certain ownership thresholds triggers public filing and disclosure obligations and signals potential control or influence, much like having the keys to a car implies you can drive it even if it’s registered to someone else.

Schedule 13G regulatory

"This amendment refers to a filed with the on December 17, 2025"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What percentage of C3is Inc. (CISS) does L1 Capital Global Opportunities Master Fund own?

L1 Capital Global Opportunities Master Fund reports beneficial ownership of 1.7% of C3is Inc. common stock, representing 223,038 shares. This percentage is calculated based on 13,082,612 C3is common shares outstanding as referenced in a July 28, 2026 prospectus.

How many C3is Inc. (CISS) shares does L1 Capital report as beneficially owned?

L1 Capital reports beneficial ownership of 223,038 C3is Inc. common shares. These are tied to Series B-2 warrants, Series C-2 warrants and other warrants to purchase common shares, all held with sole voting and dispositive power.

What is the basis for the 1.7% ownership calculation in C3is Inc. (CISS)?

The 1.7% ownership figure is based on 13,082,612 C3is Inc. common shares outstanding. That outstanding share count comes from a C3is prospectus filed under Rule 424(b)(4) dated July 28, 2026, which L1 Capital cites for its percentage calculation.

Does L1 Capital have sole or shared voting power over its C3is Inc. (CISS) holdings?

L1 Capital reports sole voting power and sole dispositive power over all 223,038 C3is Inc. shares. It reports zero shared voting power and zero shared dispositive power, indicating exclusive control over voting and disposition of the reported securities.

Who signs the C3is Inc. (CISS) Schedule 13G/A for L1 Capital and what do they disclose?

The filing is signed by David Feldman, a Director of L1 Capital Global Opportunities Master Fund, Ltd. The filing states that David Feldman and Joel Arber may be deemed to beneficially own the securities but each disclaims beneficial ownership except for any pecuniary interest.

Has L1 Capital’s C3is Inc. (CISS) stake fallen below 5% of the class?

Yes. The amendment states Ownership of 5 percent or less of a class for C3is Inc. common stock. L1 Capital’s reported beneficial ownership is 1.7%, confirming that its holdings are below the 5% Schedule 13D/G reporting threshold for large positions.

AI-generated analysis. How Rhea-AI works. Not financial advice.

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 08/14/2026 - 04:18 PM Accepted by SEC EDGAR 08/14/2026 - 04:10 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

C3is Inc.

(Name of Issuer)

Common Stock, $0.01 par value

(Title of Class of Securities)

Y18284169

(CUSIP Number)

08/14/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): Y18284169

1

Names of Reporting Persons

L1 Capital Global Opportunities Master Fund, Ltd.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 223,038.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 223,038.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

223,038.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

1.7 %

12

Type of Reporting Person (See Instructions)

FI

SCHEDULE 13G

Item 1.
(a)	Name of issuer: C3is Inc.
(b)	Address of issuer's principal executive offices: 331 Kifissias Avenue Erithrea, 14561 Athens, Greece
Item 2.
(a)	Name of person filing: L1 Capital Global Opportunities Master Fund, Ltd.
(b)	Address or principal business office or, if none, residence: 3rd Floor, Citrus Grove Building, 106 Goring Ave. George Town PO Box 10085 Grand Cayman, Cayman Islands KY1-1001
(c)	Citizenship: Cayman Islands
(d)	Title of class of securities: Common Stock, $0.01 par value
(e)	CUSIP No.: Y18284169
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 223,038 This amendment refers to a Schedule 13G filed with the Securities and Exchange Commission on December 17, 2025, covering 443,213 Common Shares purchased on December 11, 2025. The amounts in Row (5), (7) and (9) represent 97,027 Series B-2 Warrants to purchase Common Shares, 112,617 Series C-2 Warrants to purchase Common Shares and 13,393 warrants to purchase Common Shares. The percentage set forth on Row (11) of the cover page for the reporting person is based on 13,082,612 Common Shares outstanding, based on the Issuer's Prospectus filed under Rule 424(b)(4) with the Securities and Exchange Commission on July 28, 2026. David Feldman and Joel Arber are the Directors of L1 Capital Global Opportunities Master Fund, Ltd. As such, L1 Capital Global Opportunities Master Fund, Ltd., Mr. Feldman, and Mr. Arber may be deemed to beneficially own (as that term is defined in Rule 13d-3 under the Securities Exchange Act of 1934) the issuer's securities described herein. To the extent Mr. Feldman and Mr. Arber are deemed to beneficially own such securities, Mr. Feldman and Mr. Arber disclaim beneficial ownership of these securities except to the extent of its pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 13 and the rules thereunder.
(b)	Percent of class: 1.7%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 223,038
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 223,038
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

L1 Capital Global Opportunities Master Fund, Ltd.

Signature:	/s/ David Feldman
Name/Title:	David Feldman, Director
Date:	08/14/2026