As of November 9, 2026, 2 holders' latest Schedule 13D or 13G filings report owning 5% or more of Janus Henderson Group plc. The largest reported stake is Trian Fund Management, L.P.'s, at 13%. 10 filings are on record since October 27, 2025 (Schedule 13D/A, June 30, 2026).
Sell to companies like Janus Henderson Group plc? Enter your website and see 10 with a filed reason to buy from you this month. Free.
Opens in a new tab. No signup.
Key facts
- · Reporting person: Massachusetts Mutual Life Insurance Company · Sole voting: 0 · Shared voting: 0 · Sole dispositive: 0 · Shared dispositive: 0 · SCHEDULE 13D/A, 2026-07-02
- · Holder: Trian Fund Management, L.P. · Percent: 13% · Shares: 0 · SCHEDULE 13D/A
- · Holder: Trian Fund Management, L.P. · Percent: 16.65% · SCHEDULE 13D/A
- · Holder: Trian Fund Management, L.P. · Percent: 16.65% · SCHEDULE 13D/A
- · Holder: BlackRock, Inc. · Percent: 7.5% · SCHEDULE 13G/A
Janus Henderson Group plc has 10 Schedule 13D or 13G filings on record since 2025-10-27. 2 holders' latest filing reports 5% or more of ordinary shares, $1.50 per share par value. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Trian Fund Management, L.P. | 13% | 0 | SCHEDULE 13D/A, 2026-06-30 | 2026-06-30 |
| BlackRock, Inc. | 7.5% | 11,602,573 | SCHEDULE 13G/A, 2026-04-24 | 2026-03-31 |
| Massachusetts Mutual Life Insurance Company | 0% | 0 | SCHEDULE 13D/A, 2026-07-02 | 2026-06-30 |
| The Vanguard Group | 0% | 0 | SCHEDULE 13G/A, 2026-03-26 | 2026-03-13 |
Holding shares or following this stake? See who's behind Janus Henderson Group plc and the warning signs.
Free to see. No signup.
Keep reading
More on Janus Henderson Group plc and the records around it.
Janus Henderson Group plc elsewhere on the record
- Acquisition Jun 2026
Companies that share a holder
- MASSACHUSETTS MUTUAL LIFE INSURANCE CO also filed stake reports on 1 other company: Invesco Real Estate Income Trust Inc. (Jan 2026)
- Nelson Peltz also filed stake reports on 1 other company: The Wendy's Company (Oct 2026)
- BlackRock, Inc. also filed stake reports on 1596 other companies: AvePoint, Inc. (Nov 2026), BIOMARIN PHARMACEUTICAL INC (Nov 2026), MSG RANGERS CORP (Nov 2026)
Watch Janus Henderson Group plc
Get an email when Janus Henderson Group plc files again: a new raise, a leadership change, a layoff or an IPO filing. One email first to confirm; nothing else until you click it. At most one a day, one click to stop. Free for up to 3 companies.
Want the whole picture on Janus Henderson Group plc?
Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
A Full Report on Janus Henderson Group plc: verified, sourced, every claim cited, ready in a few minutes. See pricing.
What the Full Report on Janus Henderson Group plc covers
The Short Answer
Which Company This Is
What They Do, And How The Money Works
Who Runs It, And How To Reach Them
The Money: Funding, Valuation, Runway
Who Pays Them, And Who They Are Up Against
Warning Bells
Sources
11 cited sources found
Plus the sections for what you are deciding, which you pick after ordering.
A real finished report, first screen. Opens in a new tab.
Not ready to order yet? Keep this snapshot.
Sends this preview to you once; we won't add you to any list
Voting and dispositive power, as filed
| Reporting person | Sole voting | Shared voting | Sole dispositive | Shared dispositive | Filing |
|---|---|---|---|---|---|
| Nelson Peltz | 0 | 0 | 0 | 0 | SCHEDULE 13D/A, 2026-06-30 |
| Peter W. May | 0 | 0 | 0 | 0 | SCHEDULE 13D/A, 2026-06-30 |
| Trian Fund Management, L.P. | 0 | 0 | 0 | 0 | SCHEDULE 13D/A, 2026-06-30 |
| Trian Fund Management GP, LLC | 0 | 0 | 0 | 0 | SCHEDULE 13D/A, 2026-06-30 |
| Trian Partners AM Holdco II, Ltd. | 0 | 0 | 0 | 0 | SCHEDULE 13D/A, 2026-06-30 |
| Massachusetts Mutual Life Insurance Company | 0 | 0 | 0 | 0 | SCHEDULE 13D/A, 2026-07-02 |
The latest filing identifies Janus Henderson Group plc by CUSIP G4474Y214 and gives its principal executive office as 201 Bishopsgate, London (SCHEDULE 13D/A, 2026-07-02).
Purpose of Transaction (Item 4)
Trian Fund Management, L.P.
Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following: On June 30, 2026, the transactions contemplated by the Agreement and Plan of Merger, dated December 21, 2025 (as amended by Amendment No. 1 to the Agreement and Plan of Merger, dated as of March 24, 2026 and the side letter agreement, dated as of June 16, 2026, the "Merger Agreement"), by and among Parent, Merger Sub and the Issuer were consummated. Pursuant to the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger"), and the Issuer continued as the surviving company and converted to a private limited company incorporated under the laws of Jersey and changed its name from "Janus Henderson Group plc" to "Janus Henderson Group Ltd.". At the effective time of the Merger (the "Effective Time"), each ordinary share, par value $1.50 per share, of the Issuer (an "Ordinary Share" and collectively, the "Ordinary Shares") outstanding immediately prior to the Effective Time (except for Ordinary Shares held by Parent and as otherwise provided in the Merger Agreement) was converted into the right to receive $52.00 per share in cash, without interest (the "Merger Consideration"). Immediately prior to the Effective Time, Trian Partners AM Holdco II, Ltd. and certain other funds affiliated with Trian Fund Management, L.P. ("Trian") contributed 25,136,205 Ordinary Shares to Jupiter Topco LLC ("Topco") in exchange for equity interests of Topco of equivalent value. All other …The first part of Item 4 of the SCHEDULE 13D/A filed 2026-06-30; the filing has the rest
Massachusetts Mutual Life Insurance Company
Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following: On June 30, 2026, the transactions contemplated by the Merger Agreement and the Equity Commitment Letter were consummated. As a result of the Merger, the Ordinary Shares will no longer be listed on The New York Stock Exchange and will be deregistered under Section 12(b) of the Exchange Act. Additionally, as a result of the Merger, MassMutual no longer beneficially owns any Ordinary Shares, though MassMutual retains an equity interest in the surviving company through its beneficial ownership of preferred equity interests of Topco.Item 4 of the SCHEDULE 13D/A filed 2026-07-02
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2025-10-27 | Trian Fund Management, L.P. | 20.43% | SCHEDULE 13D/A |
| 2025-12-22 | Trian Fund Management, L.P. | 20.6% | SCHEDULE 13D/A |
| 2025-12-23 | Massachusetts Mutual Life Insurance Co | 0.1% | SCHEDULE 13D |
| 2026-03-24 | Trian Fund Management, L.P. | 20.7% | SCHEDULE 13D/A |
| 2026-03-26 | The Vanguard Group | 0% | SCHEDULE 13G/A |
| 2026-04-24 | BlackRock, Inc. | 7.5% | SCHEDULE 13G/A |
| 2026-05-14 | Trian Fund Management, L.P. | 16.65% | SCHEDULE 13D/A |
| 2026-06-18 | Trian Fund Management, L.P. | 16.65% | SCHEDULE 13D/A |
| 2026-06-30 | Trian Fund Management, L.P. | 13% | SCHEDULE 13D/A |
| 2026-07-02 | Massachusetts Mutual Life Insurance Company | 0% | SCHEDULE 13D/A |
Questions about who owns Janus Henderson Group plc
Who owns Janus Henderson Group plc?
On this page, 2 holders' latest ownership filings report 5% or more of Janus Henderson Group plc: Trian Fund Management, L.P. (13%, Schedule 13D/A, filed 2026-06-30) and BlackRock, Inc. (7.5%, Schedule 13G/A, filed 2026-04-24).
Who are the largest shareholders of Janus Henderson Group plc?
By the share each holder's latest filing reports, the largest holders of Janus Henderson Group plc on this page are Trian Fund Management, L.P. (13%) and BlackRock, Inc. (7.5%).
When did Trian Fund Management, L.P. buy into Janus Henderson Group plc?
The filings give report dates, not purchase dates. The earliest filing from Trian Fund Management, L.P. on this page is the Schedule 13D/A, filed 2025-10-27, reporting 20.43%; its latest, Schedule 13D/A filed 2026-06-30, reports 13%. That earliest filing is itself an amendment, which updates an earlier report.
Is this an audit or a full list?
Neither. The ownership list on this page covers only Schedule 13D and 13G filings, which holders make once they own 5% or more of a class of shares (an amendment can report a stake that has since fallen below 5%); 10 such filings are shown here. It is not an audit and not a full cap table: holders who never reached 5% are not listed, and a stake can change after its latest filing.
Also on the record for Janus Henderson Group plc
| Date | Record | Figure | Our page | Source |
|---|---|---|---|---|
| June 30, 2026 | Acquired by Jupiter Company Limited | — | Acquisition | Source |
| June 30, 2026 | Leadership change filing (Form 8-K, Item 5.02) | — | Leadership changes | Source |
Tools for this story
Each opens in a new tab, filled in for Janus Henderson Group plc. With no account yet, you sign up free and land on the result.
Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.