Jane Street reports 1.7% stake in Octave Specialty Group

Rhea-AI Filing Summary

Jane Street Group, LLC and affiliates reported beneficial ownership of 771,384 shares of Octave Specialty Group Inc. The filing states these shares represent 1.7% of the class and that the reporting persons have shared voting and shared dispositive power over the reported shares. The cover lists three affiliated filers with Delaware organization: Jane Street Capital, LLC; Jane Street Global Trading, LLC; and Jane Street Options, LLC, with specific shared holdings shown for each affiliate.

Insights

Institutional Ownership Specialist

Large market‑making group reports a passive sub‑2% stake in OSG.

The Schedule 13G/A lists an aggregate 771,384 shares representing 1.7% of common stock, with shared voting and dispositive authority. The filing classifies holdings across affiliates, notably 420,679 shares under Jane Street Capital, LLC and 350,603 shares under Jane Street Global Trading, LLC.

This disclosure is typical for institutional holders that aggregate positions across trading and capital entities; timing and cash‑flow treatment are not stated in the excerpt.

Key Figures

Aggregate shares beneficially owned: 771,384 shares Percent of class: 1.7% Jane Street Capital holdings: 420,679 shares +2 more

5 metrics

Aggregate shares beneficially owned 771,384 shares Total reported in Schedule 13G/A

Percent of class 1.7% Percent of common stock as reported

Jane Street Capital holdings 420,679 shares Reported under Jane Street Capital, LLC

Jane Street Global Trading holdings 350,603 shares Reported under Jane Street Global Trading, LLC

Jane Street Options holdings 102 shares Reported under Jane Street Options, LLC

Key Terms

Schedule 13G/A, Beneficial ownership, Shared dispositive power

3 terms

Schedule 13G/A regulatory

"The filing is titled "SCHEDULE 13G/A" and reports beneficial ownership"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

Beneficial ownership financial

"Item 4 lists "Amount beneficially owned: 771,384.00""

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Shared dispositive power regulatory

"Item 4 shows "Shared power to dispose... 771,384.00""

FAQ

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

What stake does Jane Street report in Octave Specialty Group (OSG)?

Jane Street reports beneficial ownership of 771,384 shares, equal to 1.7% of OSG's common stock. The filing attributes holdings across multiple affiliated entities with shared voting and dispositive authority.

Which Jane Street entities are named in the 13G/A for OSG?

The filing names Jane Street Group, LLC, Jane Street Capital, LLC, Jane Street Options, LLC, and Jane Street Global Trading, LLC, each at the same New York office address.

How are voting and dispositive powers described in the filing?

The filing states the reporting persons have shared voting power and shared dispositive power over the 771,384 shares; it reports zero sole voting or sole dispositive power.

Does the Schedule 13G/A indicate Jane Street is an active trader or passive holder?

The form type is a Schedule 13G/A, which typically reports passive or institutional holdings; the filing itself lists ownership and power details but does not state trading intent or activity in the excerpt.

What are the share counts by affiliate disclosed in this filing?

The filing shows 420,679 shares for Jane Street Capital, LLC; 350,603 shares for Jane Street Global Trading, LLC; and 102 shares for Jane Street Options, LLC, summing to the reported aggregate.

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

Accepted by SEC EDGAR 05/11/2026 - 04:51 PM EDT 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)

OCTAVE SPECIALTY GROUP INC

(Name of Issuer)

Common stock par value $0.01 per share

(Title of Class of Securities)

023139884

(CUSIP Number)

03/31/2026

(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): 023139884

1

Names of Reporting Persons

JANE STREET GROUP, LLC

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 771,384.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 771,384.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

771,384.00

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)

HC

SCHEDULE 13G

CUSIP Number(s): 023139884

1

Names of Reporting Persons

Jane Street Capital, LLC

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 420,679.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 420,679.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

420,679.00

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)

0.9 %

12

Type of Reporting Person (See Instructions)

BD

SCHEDULE 13G

CUSIP Number(s): 023139884

1

Names of Reporting Persons

Jane Street Options, LLC

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 102.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 102.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

102.00

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)

0.0 %

12

Type of Reporting Person (See Instructions)

BD

SCHEDULE 13G

CUSIP Number(s): 023139884

1

Names of Reporting Persons

Jane Street Global Trading, LLC

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 350,603.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 350,603.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

350,603.00

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)

0.8 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

Item 1.
(a)	Name of issuer: OCTAVE SPECIALTY GROUP INC
(b)	Address of issuer's principal executive offices: 40 WALL STREET, 40 WALL STREET, NEW YORK, NEW YORK, 10005.
Item 2.
(a)	Name of person filing: Jane Street Group, LLC; Jane Street Capital, LLC; Jane Street Options, LLC; Jane Street Global Trading, LLC
(b)	Address or principal business office or, if none, residence: Jane Street Group, LLC 250 Vesey Street 6th Floor New York, NY 10281 Jane Street Capital, LLC 250 Vesey Street 6th Floor New York, NY 10281 Jane Street Options, LLC 250 Vesey Street 6th Floor New York, NY 10281 Jane Street Global Trading, LLC 250 Vesey Street 6th Floor New York, NY 10281
(c)	Citizenship: See Item 4 of Cover Page
(d)	Title of class of securities: Common stock par value $0.01 per share
(e)	CUSIP No.: 023139884
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: 771,384.00
(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: 0
	(ii) Shared power to vote or to direct the vote: 771,384.00
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 771,384.00
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.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. Subsidiary: Jane Street Capital, LLC - (a) Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o) Jane Street Options, LLC - (a) Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o) Jane Street Global Trading, LLC - N/A
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 acquired and are held in the ordinary course of business and 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.

JANE STREET GROUP, LLC

Signature:	/s/ Jeremy Kahn
Name/Title:	Jeremy Kahn (Authorized Signatory)
Date:	05/11/2026

Jane Street Capital, LLC

Signature:	/s/ Jeremy Kahn
Name/Title:	Jeremy Kahn (Authorized Signatory)
Date:	05/11/2026

Jane Street Options, LLC

Signature:	/s/ Jeremy Kahn
Name/Title:	Jeremy Kahn (Authorized Signatory)
Date:	05/11/2026

Jane Street Global Trading, LLC

Signature:	/s/ Jeremy Kahn
Name/Title:	Jeremy Kahn (Authorized Signatory)
Date:	05/11/2026