ADAR1 Capital Management (JATT) discloses 5.4% beneficial stake in JATT II

Rhea-AI Filing Summary

ADAR1 Capital Management, LLC and Daniel Schneeberger report beneficial ownership of ordinary shares of JATT II Acquisition Corp. ADAR1-managed private investment funds hold 417,724 Ordinary Shares, and these shares may be deemed indirectly beneficially owned by both reporting persons.

The position represents 5.4% of JATT II’s Ordinary Shares, based on 7,800,000 shares outstanding as of June 30, 2026, as reported in the company’s quarterly report. Voting and dispositive power over the 417,724 shares is shared, with no sole voting or dispositive authority reported for either ADAR1 Capital Management or Mr. Schneeberger.

Key Figures

Shares beneficially owned: 417,724 shares Percent of class: 5.4% Shares outstanding: 7,800,000 shares

3 metrics

Shares beneficially owned 417,724 shares Ordinary Shares of JATT II Acquisition Corp. held by ADAR1-managed funds

Percent of class 5.4% Portion of JATT II Ordinary Shares beneficially owned by the reporting persons

Shares outstanding 7,800,000 shares JATT II Ordinary Shares outstanding as of June 30, 2026

Key Terms

beneficially owned, shared voting power, shared dispositive power, investment adviser, +1 more

5 terms

beneficially owned financial

"The amounts reported in boxes 6, 8, and 9 represent 417,724 shares ... may be deemed to be indirectly beneficially owned"

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 417,724.00 ... represent 417,724 shares of ordinary shares"

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 417,724.00 ... represent 417,724 shares of ordinary shares"

investment adviser financial

"ADAR1 Capital Management, an investment adviser as described in SS 240.13d-1(b)(1)(ii)(E)"

An investment adviser is a person or firm that professionally manages money and gives recommendations about buying, selling, or holding investments. Like a financial coach or guide, they have a legal duty to act in a client's best financial interest, so their advice, fees and potential conflicts can directly affect returns and risk — making their role important for investors who want informed, accountable help with portfolios.

control person financial

"Mr. Schneeberger is filing this as a control person in respect of shares"

A control person is an individual or entity that can significantly influence a company’s decisions and direction through ownership, voting power, or contractual rights—think of them as the captain who can steer the ship. Investors care because a control person’s choices affect corporate strategy, board appointments, and transactions that can raise or lower a stock’s value, and they often carry additional legal responsibilities and disclosure requirements to protect other shareholders.

FAQ

What percentage of JATT (JATT II Acquisition Corp.) does ADAR1 Capital Management own?

ADAR1-managed funds beneficially own 5.4% of JATT’s Ordinary Shares. This is based on 417,724 shares held versus 7,800,000 shares outstanding as of June 30, 2026, per the company’s quarterly report.

How many JATT ordinary shares are reported as beneficially owned in this Schedule 13G?

The filing reports 417,724 Ordinary Shares of JATT II Acquisition Corp. as beneficially owned. These shares are held by private investment funds managed by ADAR1 Capital Management and may be indirectly owned by both ADAR1 and Daniel Schneeberger.

Who are the reporting persons in the JATT Schedule 13G filing?

The reporting persons are ADAR1 Capital Management, LLC, a Texas limited liability company, and Daniel Schneeberger, a citizen of Switzerland. Mr. Schneeberger is the sole manager of ADAR1 and is filing as a control person of the adviser-managed funds.

What voting and dispositive powers over JATT shares are reported by ADAR1 and Daniel Schneeberger?

Both reporting persons disclose 0 shares with sole voting or dispositive power and 417,724 shares with shared voting and shared dispositive power. The shares are owned by private funds managed by ADAR1 Capital Management.

On what share count is the 5.4% ownership of JATT based?

The 5.4% ownership figure is calculated using 7,800,000 Ordinary Shares outstanding as of June 30, 2026. This outstanding share count is taken from JATT II Acquisition Corp.’s quarterly report filed in August 2026.

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

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Available on EDGAR 08/14/2026 - 09:31 PM Accepted by SEC EDGAR 08/14/2026 - 09:30 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

JATT II Acquisition Corp.

(Name of Issuer)

Ordinary Shares, par value $0.0001 per share

(Title of Class of Securities)

G50765109

(CUSIP Number)

06/30/2026

(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): G50765109

1

Names of Reporting Persons

ADAR1 Capital Management, 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

TEXAS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 417,724.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 417,724.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

417,724.00

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)

5.4 %

12

Type of Reporting Person (See Instructions)

IA, OO

Comment for Type of Reporting Person: The amounts reported in boxes 6, 8, and 9 represent 417,724 shares of ordinary shares, par value $0.0001 per share ("Ordinary Shares"), of JATT II Acquisition Corp (the "Issuer") owned directly by private investment funds managed by ADAR1 Capital Management, LLC. Such securities may be deemed to be indirectly beneficially owned by ADAR1 Capital Management, LLC. The percentage in box 11 is based on 7,800,000 Ordinary Shares outstanding as of June 30, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission on August 13, 2026.

SCHEDULE 13G

CUSIP Number(s): G50765109

1

Names of Reporting Persons

Daniel Schneeberger

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

SWITZERLAND

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 417,724.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 417,724.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

417,724.00

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)

5.4 %

12

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: The amounts reported in boxes 6, 8, and 9 represent 417,724 shares of ordinary shares, par value $0.0001 per share ("Ordinary Shares"), of JATT II Acquisition Corp (the "Issuer") owned directly by private investment funds managed by ADAR1 Capital Management, LLC. Such securities may be deemed to be indirectly beneficially owned by Daniel Schneeberger, the sole manager of ADAR1 Capital Management, LLC. The percentage in box 11 is based on 7,800,000 Ordinary Shares outstanding as of June 30, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission on August 13, 2026.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: JATT II Acquisition Corp.
(b)	Address of issuer's principal executive offices: 153 Central Avenue, C/O 56, Westfield, NJ 07091
Item 2.
(a)	Name of person filing: This Schedule is being filed on behalf of each of the following persons (each, a "Reporting Person" and collectively, the "Reporting Persons"): (i) ADAR1 Capital Management, LLC ("ADAR1 Capital Management"); and (ii) Daniel Schneeberger ("Mr. Schneeberger").
(b)	Address or principal business office or, if none, residence: The address of the principal business office of each of the Reporting Persons is 3503 Wild Cherry Drive, Building 9, Austin, Texas 78738.
(c)	Citizenship: (i) ADAR1 Capital Management is a Texas limited liability company; and (ii) Mr. Schneeberger is a citizen of Switzerland.
(d)	Title of class of securities: Ordinary Shares, par value $0.0001 per share
(e)	CUSIP Number(s): G50765109
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: The information contained on the cover pages of this Schedule 13G is incorporated herein by reference.
(b)	Percent of class: The information contained on the cover pages of this Schedule 13G is incorporated herein by reference.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: The information contained on the cover pages of this Schedule 13G is incorporated herein by reference.
	(ii) Shared power to vote or to direct the vote: The information contained on the cover pages of this Schedule 13G is incorporated herein by reference.
	(iii) Sole power to dispose or to direct the disposition of: The information contained on the cover pages of this Schedule 13G is incorporated herein by reference.
	(iv) Shared power to dispose or to direct the disposition of: The information contained on the cover pages of this Schedule 13G is incorporated herein by reference.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
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. Mr. Schneeberger is filing this Schedule 13G as a control person in respect of shares beneficially owned by ADAR1 Capital Management, an investment adviser as described in SS 240.13d-1(b)(1)(ii)(E).
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.

ADAR1 Capital Management, LLC

Signature:	/s/ Daniel Schneeberger
Name/Title:	Daniel Schneeberger, Manager
Date:	08/14/2026

Daniel Schneeberger

Signature:	/s/ Daniel Schneeberger
Name/Title:	Daniel Schneeberger, in his individual capacity
Date:	08/14/2026

Exhibit Information

Exhibit A: Joint Filing Agreement