JHG

Represents a deemed acquisition of shares of the Issuer underlying outstanding and unvested performance restricted stock unit awards ("Unvested PSU Awards") held by the Reporting Person as of immediately prior to the Effective Time based on a deemed satisfaction of the applicable performance goals at 120% of target pursuant to the Merger Agreement.

At the Effective Time, each Unvested PSU Award held by the Reporting Person was converted into the contingent right to receive a cash award of equivalent value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested PSU Award immediately prior to the Effective Time (with any applicable performance goals deemed satisfied at 120% of target), plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement PSU Award"). Following the Effective Time, the value of each Replacement PSU Award will be determined by reference to the value of the applicable class of equity securities of TopCo and will be settled in cash or in equity interests in TopCo.

Represents a deemed acquisition of shares of the Issuer underlying outstanding and unvested performance restricted stock unit awards ("Unvested PSU Awards") held by the Reporting Person as of immediately prior to the Effective Time based on a deemed satisfaction of the applicable performance goals at 120% of target pursuant to the Merger Agreement, except in the case of the Unvested PSU Award granted to the Reporting Person on May 12, 2025 (the "Special PSU Award"), for which performance goals were deemed satisfied at 100% of target pursuant to the related award agreement.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 3,288 outstanding restricted stock units ("RSUs") held by the Reporting Person that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer's common stock subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 3,288 outstanding restricted stock units ("RSUs") held by the Reporting Person that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer's common stock subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

Immediately prior to the Effective Time, the Reporting Person and Sundance Investments Inc. contributed 5,793 and 14,900 ordinary shares of the Issuer, respectively, to Jupiter Topco LLC ("Topco") in exchange for equity interests of Topco of equivalent value.

Shares are held by Sundance Investments Inc., an investment trust under which the Reporting Person is the sole shareholder.

Immediately prior to the Effective Time, the Reporting Person contributed 9,664 ordinary shares of the Issuer to Topco in exchange for equity interests of Topco of equivalent value.

Represents a deemed acquisition of shares of the Issuer underlying outstanding and unvested performance restricted stock unit awards ("Unvested PSU Awards") held by the Reporting Person as of immediately prior to the Effective Time based on a deemed satisfaction of the applicable performance goals at 120% of target pursuant to the Merger Agreement.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes shares purchased under the Issuer's Employee Stock Purchase Plan.

Due to an administrative error, the Reporting Person's Form 4 filed on March 3, 2026 inadvertently overstated the amount of securities beneficially owned following reported transactions by 19,837 shares. The amount reported in Column 5 reports the correct amount of securities beneficially owned.

Represents a deemed acquisition of shares of the Issuer underlying outstanding and unvested performance restricted stock unit awards ("Unvested PSU Awards") held by the Reporting Person as of immediately prior to the Effective Time based on a deemed satisfaction of the applicable performance goals at 120% of target pursuant to the Merger Agreement.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent") and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name 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 (the "Ordinary Shares") (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 Ordinary Share in cash, without interest (the "Merger Consideration")

Represents Ordinary Shares beneficially owned by the Trian Funds that were converted into the right to receive the Merger Consideration.

Trian Management serves as the management company for the Trian Funds and as such determines the investment and voting decisions of the Trian Funds with respect to the shares of the Issuer which they hold. Mr. Baldwin is a member of the Investment Committee and a partner of Trian Management, and a limited partner or member of certain affiliates of the Trian Funds and as such has an indirect interest in the shares of the Issuer held by the Trian Funds. The Reporting Persons disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein and this report shall not be deemed an admission that the Reporting Persons are the beneficial owner of such securities for purposes of Section 16 or for any other purpose. Mr. Baldwin is a director of the Issuer.

At the Effective Time, the Special PSU Award held by the Reporting Person was converted into the contingent right to receive a cash payment (with performance goals deemed satisfied at 100% of target pursuant to the related award agreement) equal to the initial value as of the Effective Time earning interest at the Replacement Award Interest Rate or to be notionally invested in an underlying mutual fund or funds selected by the Reporting Person from a list of approved mutual fund options.

At the Effective Time, the Special RSU Award held by the Reporting Person was converted into the contingent right to receive a cash payment equal to the initial value as of the Effective Time earning interest at the Replacement Award Interest Rate (as defined in the Merger Agreement) or to be notionally invested in an underlying mutual fund or funds selected by the Reporting Person from a list of approved mutual fund options.

At the Effective Time, each outstanding and unvested restricted stock unit award (each, an "Unvested RSU Award") held by the Reporting Person was converted into the contingent right to receive an equity-based award with an initial value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested RSU Award immediately prior to the Effective Time, plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement RSU Award"). Following the Effective Time, the value of each Replacement RSU Award will be determined by reference to the value of the applicable class of equity securities of Jupiter Topco LLC ("TopCo") and will be settled in cash or in equity interests in TopCo.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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"). Includes shares purchased under the Issuer's Employee Stock Purchase Plan.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 3,288 outstanding restricted stock units ("RSUs") held by the Reporting Person that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer's common stock subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

At the Effective Time, each outstanding and unvested restricted stock unit award (each, an "Unvested RSU Award") held by the Reporting Person was converted into the contingent right to receive an equity-based award with an initial value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested RSU Award immediately prior to the Effective Time, plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement RSU Award"). Following the Effective Time, the value of each Replacement RSU Award will be determined by reference to the value of the applicable class of equity securities of Jupiter Topco LLC ("TopCo") and will be settled in cash or in equity interests in TopCo.

At the Effective Time, each outstanding and unvested restricted stock unit award (each, an "Unvested RSU Award") held by the Reporting Person, except for the Unvested RSU Award granted to the Reporting Person on May 12, 2025 (the "Special RSU Award"), was converted into the contingent right to receive an equity-based award with an initial value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested RSU Award immediately prior to the Effective Time, plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement RSU Award"). Following the Effective Time, the value of each Replacement RSU Award will be determined by reference to the value of the applicable class of equity securities of Jupiter Topco LLC ("TopCo") and will be settled in cash or in equity interests in TopCo.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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"). Includes shares purchased under the Issuer's Employee Stock Purchase Plan.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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"). Includes shares purchased under the Issuer's Employee Stock Purchase Plan.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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"). Includes shares acquired under the Issuer's Save As You Earn Plan and shares purchased under the Issuer's Buy As You Earn Plan.

At the Effective Time, each Unvested PSU Award held by the Reporting Person was converted into the contingent right to receive a cash award of equivalent value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested PSU Award immediately prior to the Effective Time (with any applicable performance goals deemed satisfied at 120% of target), plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement PSU Award"). Following the Effective Time, the value of each Replacement PSU Award will be determined by reference to the value of the applicable class of equity securities of TopCo and will be settled in cash or in equity interests in TopCo.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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"). Includes shares purchased under the Issuer's Employee Stock Purchase Plan.

Due to an administrative error, the Reporting Person's Form 4 filed on March 3, 2026 inadvertently understated the amount of securities beneficially owned following reported transactions by 1,311 shares. The amount reported in Column 5 reports the correct amount of securities beneficially owned.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 3,288 outstanding restricted stock units ("RSUs") held by the Reporting Person that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer's common stock subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

At the Effective Time, each outstanding and unvested restricted stock unit award (each, an "Unvested RSU Award") held by the Reporting Person was converted into the contingent right to receive an equity-based award with an initial value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested RSU Award immediately prior to the Effective Time, plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement RSU Award"). Following the Effective Time, the value of each Replacement RSU Award will be determined by reference to the value of the applicable class of equity securities of Jupiter Topco LLC ("TopCo") and will be settled in cash or in equity interests in TopCo.

At the Effective Time, each outstanding and unvested restricted stock unit award (each, an "Unvested RSU Award") held by the Reporting Person was converted into the contingent right to receive an equity-based award with an initial value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested RSU Award immediately prior to the Effective Time, plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement RSU Award"). Following the Effective Time, the value of each Replacement RSU Award will be determined by reference to the value of the applicable class of equity securities of Jupiter Topco LLC ("TopCo") and will be settled in cash or in equity interests in TopCo.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 23,504 outstanding restricted stock units ("RSUs") held by the Reporting Person (including dividend equivalents in the form of RSUs) that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent") and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name 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 (the "Ordinary Shares") (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 Ordinary Share in cash, without interest (the "Merger Consideration")

Immediately prior to the Effective Time, certain funds (the "Trian Funds") managed by Trian Fund Management, L.P. ("Trian Management") contributed 25,136,205 Ordinary Shares to Jupiter Topco LLC ("Topco") in exchange for equity interests of Topco of equivalent value.

Trian Management serves as the management company for the Trian Funds and as such determines the investment and voting decisions of the Trian Funds with respect to the shares of the Issuer which they hold. Mr. Frank is a member of the Investment Committee and a partner of Trian Management, and a limited partner or member of certain affiliates of the Trian Funds and as such has an indirect interest in the shares of the Issuer held by the Trian Funds. The Reporting Persons disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein and this report shall not be deemed an admission that the Reporting Persons are the beneficial owner of such securities for purposes of Section 16 or for any other purpose. Mr. Frank is a director of the Issuer.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 3,288 outstanding restricted stock units ("RSUs") held by the Reporting Person that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

Immediately prior to the Effective Time, the Reporting Person and Sundance Investments Inc. contributed 5,793 and 14,900 ordinary shares of the Issuer, respectively, to Jupiter Topco LLC ("Topco") in exchange for equity interests of Topco of equivalent value.

At the Effective Time, each Unvested PSU Award held by the Reporting Person was converted into the contingent right to receive a cash award of equivalent value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested PSU Award immediately prior to the Effective Time (with any applicable performance goals deemed satisfied at 120% of target), plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement PSU Award"). Following the Effective Time, the value of each Replacement PSU Award will be determined by reference to the value of the applicable class of equity securities of TopCo and will be settled in cash or in equity interests in TopCo.

At the Effective Time, each Unvested PSU Award held by the Reporting Person, except for the Special PSU Award, was converted into the contingent right to receive a cash award of equivalent value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested PSU Award immediately prior to the Effective Time (with any applicable performance goals deemed satisfied at 120% of target), plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement PSU Award"). Following the Effective Time, the value of each Replacement PSU Award will be determined by reference to the value of the applicable class of equity securities of TopCo and will be settled in cash or in equity interests in TopCo.

At the Effective Time, each Unvested PSU Award held by the Reporting Person was converted into the contingent right to receive a cash award of equivalent value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested PSU Award immediately prior to the Effective Time (with any applicable performance goals deemed satisfied at 120% of target), plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement PSU Award"). Following the Effective Time, the value of each Replacement PSU Award will be determined by reference to the value of the applicable class of equity securities of TopCo and will be settled in cash or in equity interests in TopCo.

Immediately prior to the Effective Time, the Reporting Person contributed 9,664 ordinary shares of the Issuer to Jupiter Topco LLC ("Topco") in exchange for equity interests of Topco of equivalent value.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 3,288 outstanding restricted stock units ("RSUs") held by the Reporting Person that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer's common stock subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent") and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name 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 (the "Ordinary Shares") (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 Ordinary Share in cash, without interest (the "Merger Consideration")

Represents Ordinary Shares beneficially owned by the Trian Funds that were converted into the right to receive the Merger Consideration.

Trian Management serves as the management company for the Trian Funds and as such determines the investment and voting decisions of the Trian Funds with respect to the shares of the Issuer which they hold. Mr. Frank is a member of the Investment Committee and a partner of Trian Management, and a limited partner or member of certain affiliates of the Trian Funds and as such has an indirect interest in the shares of the Issuer held by the Trian Funds. The Reporting Persons disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein and this report shall not be deemed an admission that the Reporting Persons are the beneficial owner of such securities for purposes of Section 16 or for any other purpose. Mr. Frank is a director of the Issuer.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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").

Includes 3,288 outstanding restricted stock units ("RSUs") held by the Reporting Person that were cancelled as of immediately prior to the Effective Time and were exchanged for the right to receive a lump sum cash payment equal to (a)(1) the Merger Consideration, multiplied by (2) the number of shares of the Issuer's common stock subject to such RSUs immediately prior to the Effective Time, plus (b) the amount of any accrued but unpaid dividend equivalent rights.

At the Effective Time, each outstanding and unvested restricted stock unit award (each, an "Unvested RSU Award") held by the Reporting Person was converted into the contingent right to receive an equity-based award with an initial value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested RSU Award immediately prior to the Effective Time, plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement RSU Award"). Following the Effective Time, the value of each Replacement RSU Award will be determined by reference to the value of the applicable class of equity securities of Jupiter Topco LLC ("TopCo") and will be settled in cash or in equity interests in TopCo.

Represents a deemed acquisition of shares of the Issuer underlying outstanding and unvested performance restricted stock unit awards ("Unvested PSU Awards") held by the Reporting Person as of immediately prior to the Effective Time based on a deemed satisfaction of the applicable performance goals at 120% of target pursuant to the Merger Agreement.

At the Effective Time, each outstanding and unvested restricted stock unit award (each, an "Unvested RSU Award") held by the Reporting Person was converted into the contingent right to receive an equity-based award with an initial value equal to (i)(a) the Merger Consideration, multiplied by (b) the number of shares of the Issuer subject to such Unvested RSU Award immediately prior to the Effective Time, plus (ii) the amount of any accrued but unpaid dividend equivalent rights (each, a "Replacement RSU Award"). Following the Effective Time, the value of each Replacement RSU Award will be determined by reference to the value of the applicable class of equity securities of Jupiter Topco LLC ("TopCo") and will be settled in cash or in equity interests in TopCo.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent") and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name 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 (the "Ordinary Shares") (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 Ordinary Share in cash, without interest (the "Merger Consideration")

Immediately prior to the Effective Time, certain funds (the "Trian Funds") managed by Trian Fund Management, L.P. ("Trian Management") contributed 25,136,205 Ordinary Shares to Jupiter Topco LLC ("Topco") in exchange for equity interests of Topco of equivalent value.

Trian Management serves as the management company for the Trian Funds and as such determines the investment and voting decisions of the Trian Funds with respect to the shares of the Issuer which they hold. Mr. Baldwin is a member of the Investment Committee and a partner of Trian Management, and a limited partner or member of certain affiliates of the Trian Funds and as such has an indirect interest in the shares of the Issuer held by the Trian Funds. The Reporting Persons disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein and this report shall not be deemed an admission that the Reporting Persons are the beneficial owner of such securities for purposes of Section 16 or for any other purpose. Mr. Baldwin is a director of the Issuer.

On June 30, 2026, pursuant to that certain Agreement and Plan of Merger, dated as of December 21, 2025 (as amended, including by Amendment No. 1 dated March 24, 2026, and a side letter dated June 16, 2026, the "Merger Agreement"), among the Issuer, Jupiter Company Limited ("Parent"), and Jupiter Merger Sub Limited ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Parent and changing its name to "Janus Henderson Group Ltd." At the effective time of the Merger (the "Effective Time"), each ordinary share of the Issuer (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"). Includes shares purchased under the Issuer's Employee Stock Purchase Plan.

Represents the number of shares withheld by the Issuer to satisfy the Reporting Person's tax withholding obligations in connection with the vesting of restricted stock units granted on May 2, 2025.

Represents the number of shares withheld by the Issuer to satisfy the Reporting Person's tax withholding obligations in connection with the vesting of restricted stock units granted on May 2, 2025.

Represents the number of shares withheld by the Issuer to satisfy the Reporting Person's tax withholding obligations in connection with the vesting of restricted stock units granted on May 2, 2025.

Represents the number of shares withheld by the Issuer to satisfy the Reporting Person's tax withholding obligations in connection with the vesting of restricted stock units granted on May 2, 2025.

The sale reported in this Form 4 was done for portfolio management purposes by certain funds (the "Trian Funds") managed by Trian Fund Management, L.P. ("Trian Management") which primarily hold publicly traded securities. As contemplated by the Voting and Rollover Agreement dated as of December 21, 2025, entered into by and among the Issuer and the other parties thereto, an affiliate of Trian Management will roll over at least 24,750,000 shares of the Issuer in connection with the closing of the previously announced acquisition of the Issuer by Trian Management and its affiliated funds, and General Catalyst and its affiliated funds. Progress toward closing is continuing, with the Issuer's shareholders approving the acquisition on April 16, 2026. The transaction is expected to close in mid-2026, subject to customary closing conditions, including receipt of applicable regulatory approvals and client consents.

Trian Management serves as the management company for the Trian Funds and as such determines the investment and voting decisions of the Trian Funds with respect to the shares of the Issuer which they hold. Mr. Baldwin is a member of the Investment Committee and a partner of Trian Management, and a limited partner or member of certain affiliates of the Trian Funds and as such has an indirect interest in the shares of the Issuer held by the Trian Funds. The Reporting Persons disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein and this report shall not be deemed an admission that the Reporting Persons are the beneficial owner of such securities for purposes of Section 16 or for any other purpose. Mr. Baldwin is a director of the Issuer.

Represents the number of shares withheld by the Issuer to satisfy the Reporting Person's tax withholding obligations in connection with the vesting of restricted stock units granted on May 2, 2025.

The sale reported in this Form 4 was done for portfolio management purposes by certain funds (the "Trian Funds") managed by Trian Fund Management, L.P. ("Trian Management") which primarily hold publicly traded securities. As contemplated by the Voting and Rollover Agreement dated as of December 21, 2025, entered into by and among the Issuer and the other parties thereto, an affiliate of Trian Management will roll over at least 24,750,000 shares of the Issuer in connection with the closing of the previously announced acquisition of the Issuer by Trian Management and its affiliated funds, and General Catalyst and its affiliated funds. Progress toward closing is continuing, with the Issuer's shareholders approving the acquisition on April 16, 2026. The transaction is expected to close in mid-2026, subject to customary closing conditions, including receipt of applicable regulatory approvals and client consents.

Trian Management serves as the management company for the Trian Funds and as such determines the investment and voting decisions of the Trian Funds with respect to the shares of the Issuer which they hold. Mr. Frank is a member of the Investment Committee and a partner of Trian Management, and a limited partner or member of certain affiliates of the Trian Funds and as such has an indirect interest in the shares of the Issuer held by the Trian Funds. The Reporting Persons disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein and this report shall not be deemed an admission that the Reporting Persons are the beneficial owner of such securities for purposes of Section 16 or for any other purpose. Mr. Frank is a director of the Issuer.