STOCK TITAN

C3is Inc. (CISS) draws new Jane Street stake above 5%

(Neutral)
(Neutral)
Form Type
SCHEDULE 13G

Rhea-AI Filing Summary

C3is Inc. (CISS) has a new significant shareholder disclosure. Jane Street Group, LLC, together with its subsidiaries Jane Street Capital, LLC and Jane Street Global Trading, LLC, reports beneficial ownership of 937,330 shares of C3is Inc. common stock, representing 7.2% of the outstanding class. All of these shares are held with shared voting and dispositive power; none are held with sole power. Within this total, Jane Street Capital, LLC is reported to beneficially own 678,960 shares (5.2%) and Jane Street Global Trading, LLC 258,370 shares (2.0%). The filing identifies Jane Street Group, LLC as the parent holding company, with the two subsidiaries as the entities that acquired the securities.

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Total shares beneficially owned 937,330 shares Beneficial ownership by Jane Street Group, LLC and subsidiaries in C3is Inc. common stock
Percent of class owned 7.2% Percentage of C3is Inc. common stock beneficially owned by Jane Street Group, LLC
Shares with shared voting power 937,330 shares Number of shares over which Jane Street entities have shared voting power
Jane Street Capital holdings 678,960 shares C3is Inc. shares beneficially owned by Jane Street Capital, LLC (5.2% of class)
Jane Street Global Trading holdings 258,370 shares C3is Inc. shares beneficially owned by Jane Street Global Trading, LLC (2.0% of class)
Sole voting power 0 shares Shares of C3is Inc. over which Jane Street entities report sole voting power
Sole dispositive power 0 shares Shares of C3is Inc. over which Jane Street entities report sole dispositive power
beneficially owned financial
"Item 4. | Ownership (a) | Amount beneficially owned: 937,330.00"
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
shared voting power financial
"Shared Voting Power 937,330.00"
Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.
shared dispositive power financial
"Shared Dispositive Power 937,330.00"
parent holding company financial
"If a parent holding company has filed this schedule, pursuant to (ii)(G)..."

FAQ

What percentage of C3is Inc. (CISS) does Jane Street Group report owning?

Jane Street Group, LLC reports beneficial ownership of 7.2% of C3is Inc.'s common stock. This corresponds to 937,330 shares held with shared voting and dispositive power through its subsidiaries Jane Street Capital, LLC and Jane Street Global Trading, LLC.

How many C3is Inc. (CISS) shares does Jane Street Group beneficially own?

Jane Street Group, LLC reports beneficial ownership of 937,330 C3is Inc. common shares. All of these shares are reported with shared voting and shared dispositive power, and none are reported with sole voting or dispositive power by Jane Street entities.

What is Jane Street Capital, LLC’s ownership stake in C3is Inc. (CISS)?

Jane Street Capital, LLC reports beneficial ownership of 678,960 C3is Inc. shares, equal to 5.2% of the common stock. These shares are held with shared voting and shared dispositive power under the broader Jane Street Group, LLC structure.

What is Jane Street Global Trading, LLC’s ownership stake in C3is Inc. (CISS)?

Jane Street Global Trading, LLC reports beneficial ownership of 258,370 C3is Inc. shares, representing 2.0% of the common stock. These shares also carry shared voting and shared dispositive power rather than sole authority by the subsidiary.

Does Jane Street Group have sole or shared voting power over its C3is Inc. (CISS) shares?

Jane Street entities report 0 shares with sole voting power and 937,330 shares with shared voting power. They likewise report 0 shares with sole dispositive power and the same 937,330 shares with shared dispositive power.

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

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Learn about SEC filing dates





Y18284300

(CUSIP Number)
08/13/2026

(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





SCHEDULE 13G





SCHEDULE 13G





SCHEDULE 13G



JANE STREET GROUP, LLC
Signature:/s/ Jeremy Kahn
Name/Title:Jeremy Kahn (Authorized Signatory)
Date:08/19/2026
Jane Street Capital, LLC
Signature:/s/ Jeremy Kahn
Name/Title:Jeremy Kahn (Authorized Signatory)
Date:08/19/2026
Jane Street Global Trading, LLC
Signature:/s/ Jeremy Kahn
Name/Title:Jeremy Kahn (Authorized Signatory)
Date:08/19/2026