Jane Street Discloses 10.06M Shares (8.2%) in ALT5 Sigma Corp

Rhea-AI Filing Summary

Jane Street Group and affiliates report beneficial ownership of ALT5 Sigma Corp common stock totaling 10,061,351 shares, representing 8.2% of the class. The ownership reported is held with shared voting and dispositive power rather than sole control. The filing identifies four related reporting persons—Jane Street Group, LLC; Jane Street Global Trading, LLC; Jane Street Capital, LLC; and Jane Street Options, LLC—with the largest holdings attributed to the Group and Global Trading affiliate. The statement clarifies these positions are not intended to change or influence control of the issuer and lists the issuer's principal executive office.

Positive

• Material disclosure of >5% ownership (8.2%) enhances market transparency
• Detailed breakdown across Jane Street affiliates clarifies allocation of voting and dispositive power
• Certification that holdings are not intended to change or influence control provides clarity on filer intent

Negative

• None.

Insights

Financial Analyst

TL;DR: A notable 8.2% stake by Jane Street affiliates signals a meaningful passive position that could affect liquidity and voting blocs.

The filing shows a consolidated beneficial ownership of 10,061,351 shares held with shared voting and dispositive power, which indicates coordinated control rights among Jane Street entities rather than sole control by any single affiliate. For investors, a >5% disclosure is material because it can influence share supply, trading dynamics, and potential board or governance engagement even when the filer disclaims intent to influence control. The breakdown across trading, capital and options affiliates suggests holdings arise from trading and market-making activities rather than a single strategic acquisition.

Corporate Governance Expert

TL;DR: The group-level disclosure and certification limit suggests a passive position but creates a visible voting bloc representing 8.2% of shares.

The schedule is filed under the passive-investor framework and includes a certification that the shares were not acquired to change control. Nonetheless, the presence of shared voting power across related entities should be monitored by the issuer and investors for potential coordination in shareholder votes. The filing appropriately identifies the subsidiaries and classifies each reporting person, supporting transparency in governance reporting.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

ALT5 Sigma Corp

(Name of Issuer)

Common Stock, $0.001 par value per share

(Title of Class of Securities)

47089W104

(CUSIP Number)

08/12/2025

(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)

SCHEDULE 13G

CUSIP No. 47089W104

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 10,061,351.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 10,061,351.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

10,061,351.00

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)

8.2 %

12

Type of Reporting Person (See Instructions)

HC

SCHEDULE 13G

CUSIP No. 47089W104

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 46,597.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 46,597.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

46,597.00

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 No. 47089W104

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 13,300.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 13,300.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

13,300.00

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 No. 47089W104

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 10,001,454.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 10,001,454.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

10,001,454.00

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)

8.2 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

Item 1.
(a)	Name of issuer: ALT5 Sigma Corp
(b)	Address of issuer's principal executive offices: 325 E. WARM SPRINGS ROAD, SUITE 102, LAS VEGAS, NEVADA, 89119.
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, $0.001 par value per share
(e)	CUSIP No.: 47089W104
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: 10061351
(b)	Percent of class: 8.2 %
(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: 10061351
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 10061351
Item 5.	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 Jane Street Global Trading, LLC Jane Street Options, LLC
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.

JANE STREET GROUP, LLC

Signature:	Jim Dieterich
Name/Title:	Managing Director
Date:	08/19/2025

Jane Street Capital, LLC

Signature:	Jim Dieterich
Name/Title:	Managing Director
Date:	08/19/2025

Jane Street Options, LLC

Signature:	Jim Dieterich
Name/Title:	Managing Director
Date:	08/19/2025

Jane Street Global Trading, LLC

Signature:	Jim Dieterich
Name/Title:	Managing Director
Date:	08/19/2025

FAQ

How many ALT5 Sigma Corp shares does Jane Street Group report owning?

The filing reports 10,061,351 shares beneficially owned by Jane Street Group and affiliates.

What percentage of ALT5 Sigma Corp does the Jane Street group own?

The aggregate position represents 8.2% of the outstanding class of common stock.

Do Jane Street affiliates hold sole voting power over these shares?

No; the filing shows 0 sole voting power and the shares are held with shared voting and dispositive power.

Which Jane Street entities are named in the Schedule 13G for ALT5 Sigma Corp?

Reported filers are Jane Street Group, LLC; Jane Street Global Trading, LLC; Jane Street Capital, LLC; and Jane Street Options, LLC.

Does the filing state the shares were acquired to influence control of the issuer?

The certification states the securities were not acquired and are not held for the purpose of changing or influencing control of the issuer.