JHG

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 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 Ordinary Shares beneficially owned by the Reporting Persons were converted into the right to receive the Merger Consideration. Also immediately prior to the Effective Time, each member of the Issuer's board of directors, including Brian Baldwin and Josh Frank, each a Partner at Trian, resigned from and ceased serving on the Issuer's board of directors. 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, the Reporting Persons no longer beneficially own any Ordinary Shares, though each of the Reporting Persons retains an equity interest in the surviving company through its beneficial ownership of equity interests of Topco.

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 Ordinary Shares beneficially owned by the Reporting Persons were converted into the right to receive the Merger Consideration. Also immediately prior to the Effective Time, each member of the Issuer's board of directors, including Brian Baldwin and Josh Frank, each a Partner at Trian, resigned from and ceased serving on the Issuer's board of directors. 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, the Reporting Persons no longer beneficially own any Ordinary Shares, though each of the Reporting Persons retains an equity interest in the surviving company through its beneficial ownership of equity interests of Topco.

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 Ordinary Shares beneficially owned by the Reporting Persons were converted into the right to receive the Merger Consideration. Also immediately prior to the Effective Time, each member of the Issuer's board of directors, including Brian Baldwin and Josh Frank, each a Partner at Trian, resigned from and ceased serving on the Issuer's board of directors. 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, the Reporting Persons no longer beneficially own any Ordinary Shares, though each of the Reporting Persons retains an equity interest in the surviving company through its beneficial ownership of equity interests of Topco.

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 Ordinary Shares beneficially owned by the Reporting Persons were converted into the right to receive the Merger Consideration. Also immediately prior to the Effective Time, each member of the Issuer's board of directors, including Brian Baldwin and Josh Frank, each a Partner at Trian, resigned from and ceased serving on the Issuer's board of directors. 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, the Reporting Persons no longer beneficially own any Ordinary Shares, though each of the Reporting Persons retains an equity interest in the surviving company through its beneficial ownership of equity interests of Topco.

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 Ordinary Shares beneficially owned by the Reporting Persons were converted into the right to receive the Merger Consideration. Also immediately prior to the Effective Time, each member of the Issuer's board of directors, including Brian Baldwin and Josh Frank, each a Partner at Trian, resigned from and ceased serving on the Issuer's board of directors. 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, the Reporting Persons no longer beneficially own any Ordinary Shares, though each of the Reporting Persons retains an equity interest in the surviving company through its beneficial ownership of equity interests of Topco.