TRIAN FUND MANAGEMENT, L.P. 4

What Happened
Brian M. Baldwin, a 10% owner of Janus Henderson Group plc (JHG) and a director, reported the sale of 6,213,418 shares on May 12, 2026. The shares were sold at $51.60 each for a total proceeds of $320,612,990. The filing indicates the sale was effected by funds managed by Trian Fund Management for portfolio management purposes (a disposition, not a purchase).

Key Details

• Transaction date and price: May 12, 2026 — 6,213,418 shares sold at $51.60 per share.
• Total value: $320,612,990.
• Transaction type: Sale (S) — open market or private sale executed by the Trian Funds (per footnote).
• Shares owned after transaction: Not specified in the provided summary of the Form 4.
• Footnotes: (F1) Sale done for portfolio management by Trian-managed funds; an affiliate will roll over at least 24,750,000 shares in connection with a pending acquisition that shareholders approved April 16, 2026, expected to close mid-2026 subject to conditions. (F2) Baldwin is a partner/member of Trian Management and disclaims direct beneficial ownership of the fund-held shares except for pecuniary interest; he also serves as a Janus Henderson director.
• Filing timeliness: No late filing indicated.

Context
This was a sale reported by a 10% owner via funds managed by Trian Fund Management, not necessarily a personal, unilateral sale by Baldwin. The filing ties the transaction to portfolio management and to an ongoing acquisition transaction in which an affiliate will roll over a substantial block of shares; the acquisition remains subject to customary closing conditions.