Janus Henderson (JBIO) discloses 3,105,669-share, 6.3% holding in Jade Biosciences

Rhea-AI Filing Summary

Janus Henderson Group plc reported beneficial ownership of 3,105,669 shares of Jade Biosciences, Inc., equal to 6.3% of the common stock. The filing states Janus Henderson holds shared voting and dispositive power over those shares and identifies Janus Henderson Biotech Innovation Master Fund Ltd. as holding more than 5%. The filing was signed on 5/15/2026.

Key Figures

Shares beneficially owned: 3,105,669 shares Percent of class: 6.3% CUSIP: 008064206 +2 more

5 metrics

Shares beneficially owned 3,105,669 shares Amount reported in Item 4

Percent of class 6.3% Percent reported in Item 4(b)

CUSIP 008064206 Common Stock CUSIP reported on cover

Shared voting power 3,105,669 shares Item 4(c)(ii) shared power to vote

Signature date 5/15/2026 Filing signed by Head of North America Compliance

Key Terms

beneficially owned, shared dispositive power, Managed Portfolios, Investment Company Act of 1940

4 terms

beneficially owned regulatory

"the Asset Managers may be deemed to be the beneficial owner of 3,105,669"

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 dispositive power regulatory

"Shared Dispositive Power 3,105,669.00"

Managed Portfolios financial

"the Asset Managers generally exercise investment and/or voting discretion on behalf of their Managed Portfolios"

Investment Company Act of 1940 regulatory

"A listing of the shareholders of an investment company registered under the Investment Company Act of 1940"

A U.S. federal law that sets the rulebook for pooled investment vehicles such as mutual funds, exchange-traded funds and similar money managers, requiring them to register with regulators, disclose holdings and fees, limit conflicts of interest, and follow governance standards. It matters to investors because these protections and transparency rules act like a referee and scoreboard, helping people compare funds, trust that managers follow fair practices, and spot hidden costs or risks.

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

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Accepted by SEC EDGAR 05/15/2026 - 12:38 PM Learn about SEC filing dates

FAQ

What stake does Janus Henderson report in JADE BIOSCIENCES (JBIO)?

Janus Henderson reports beneficial ownership of 3,105,669 shares, or 6.3%. The Schedule 13G/A states the Asset Managers exercise shared voting and dispositive power on behalf of Managed Portfolios that hold these shares.

Which Janus Henderson entity holds more than 5% of JBIO common stock?

Janus Henderson Biotech Innovation Master Fund Ltd. is named as the Managed Portfolio holding more than 5% of the common stock, per Item 6 of the filing, due to its right to receive dividends and sale proceeds.

Does Janus Henderson claim sole voting or dispositive power over JBIO shares?

No — the filing reports zero sole power and shared power of 3,105,669 shares. Item 4 lists sole voting and dispositive power as 0 and shared voting and dispositive power as 3,105,669.

When and who signed the Schedule 13G/A for JBIO?

The filing was signed by Kristin Mariani, Head of North America Compliance, on 5/15/2026. The signature block and exhibit references appear at the end of the filing excerpt.

What address is listed for Jade Biosciences in this filing?

Jade Biosciences' principal executive office is listed as 221 Crescent St., Building 23, Suite 105, MA 02453. That address appears in Item 1(b) of the Schedule 13G/A excerpt.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

JADE BIOSCIENCES, INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

008064206

(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): 008064206

1

Names of Reporting Persons

JANUS HENDERSON GROUP PLC

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

JERSEY

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,105,669.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,105,669.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,105,669.00

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)

6.3 %

12

Type of Reporting Person (See Instructions)

HC

SCHEDULE 13G

Item 1.
(a)	Name of issuer: JADE BIOSCIENCES, INC.
(b)	Address of issuer's principal executive offices: 221 CRESCENT ST., BUILDING 23, SUITE 105 WALTHAM, MA 02453
Item 2.
(a)	Name of person filing: Janus Henderson Group plc
(b)	Address or principal business office or, if none, residence: 201 Bishopsgate EC2M 3AE, United Kingdom
(c)	Citizenship: Y9
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 008064206
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: Janus Henderson Group plc (JHG) is the ultimate parent of a number of SEC-registered investment advisers and foreign equivalents thereof, including but not limited to Janus Henderson Investors US LLC, Janus Henderson Investors UK Limited, Janus Henderson Investors Australia Institutional Funds Management Limited, Janus Henderson Investors Middle East Limited, Janus Henderson Investors (Jersey) Limited, Janus Henderson Investors (Japan) Limited, Janus Henderson Investors (Singapore) Limited, Kapstream Capital Pty Limited, Privacore Capital Advisors LLC, Tabula Investment Management Limited, and Victory Park Capital Advisors LLC (each, an Asset Manager and together, the Asset Managers). The Asset Managers generally exercise investment and/or voting discretion on behalf of their clients which include investment companies, other investment advisers, institutional separate accounts and retail separate accounts (collectively referred to herein as Managed Portfolios). As a result of their exercise of investment and/or voting discretion on behalf of the Managed Portfolios, the Asset Managers may be deemed to be the beneficial owner of 3,105,669 common stock of Jade Biosciences, Inc. However, the Asset Managers do not have the right to receive any dividends from, or the proceeds from the sale of, the securities held in the Managed Portfolios and disclaim any ownership associated with such rights.
(b)	Percent of class: 6.3 %
(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: 3105669
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 3105669
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.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The Managed Portfolios have the right to receive all dividends from, and the proceeds from the sale of, the securities held in their respective accounts. Of the Managed Portfolios, only the Janus Henderson Biotech Innovation Master Fund Ltd. has the right to receive dividends from, or the proceeds from the sale of, more than five percent of the common stock of Jade Biosciences, Inc. Due to an irrevocable delegation of investment and voting discretion to an Asset Manager on less than 60 days notice, the Fund is not considered a Reporting Person under Section 13(d) and (g).
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. Please refer to Exhibit 99.
Item 8.	Identification and Classification of Members of the Group.
	If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group. N/A
Item 9.	Notice of Dissolution of Group.
	Notice of dissolution of a group may be furnished as an exhibit stating the date of the dissolution and that all further filings with respect to transactions in the security reported on will be filed, if required, by members of the group, in their individual capacity. See Item 5. N/A

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.

JANUS HENDERSON GROUP PLC

Signature:	Kristin Mariani
Name/Title:	Head of North America Compliance
Date:	5/15/2026

Exhibit Information

Exhibit 24: Power of Attorney Exhibit 99: Item 7