01—Abstract
Summary
Summary of the 8-K filed February 26, 2026. Cited figures are marked; the original filing is the authoritative source.
Affiliated Managers Group (NYSE: AMG) filed an 8-K on February 26, 2026 to announce board and leadership changes, none of which are financially material.
G. Staley Cates, former Vice Chairman of Southeastern Asset Management (and its President from 1989 to 2015), will join the Board as an independent director effective April 1, 2026. Concurrently, Karen L.
Alvingham, who has served on the Board since January 2018, will retire from the Board on the same date. The company also re-appointed Jay C. Horgen as President, effective April 1, 2026, while he continues as Chief Executive Officer.
The Cates appointment adds a seasoned, CFA-charted investor with roughly four decades of experience at Southeastern, a firm known for long-term value investing and disciplined capital allocation. Consistent with AMG's model of partnering with independent investment managers, this background may be relevant to the Board's oversight of capital allocation across AMG's affiliate portfolio. The filing discloses no related-person transactions, no family relationships, and no arrangements tied to his election, and he will receive standard director compensation and the company's standard indemnification agreement.
Horgen's re-appointment as President alongside his existing CEO role consolidates two top executive titles under one individual, which investors may view as signaling continuity in management. The filing does not disclose any change to compensation for Horgen; it incorporates his biographical and related-party information by reference to the 2025 proxy statement. AMG's stated firm-wide assets under management were approximately $813 billiona as of December 31, 2025, per the press release.
02—Key points
Key Highlights
- G. Staley Cates appointed as an independent director, effective April 1, 2026, bringing a CFA charterholder with about four decades at Southeastern Asset Management.
- Karen L. Alvingham, a director since January 2018, will retire from the Board effective April 1, 2026.
- Jay C. Horgen re-appointed as President, effective April 1, 2026, while continuing as Chief Executive Officer.
- Cates will receive the standard director compensation and enter into the company's standard director and officer indemnification agreement; no related-person transactions were disclosed.
- No familial relationships or election arrangements involving Cates were disclosed.
- AMG reported approximately $813 billion in aggregate assets under management as of December 31, 2025.
- The filing contains no financial results, guidance, or changes to Horgen's compensation.
03—Questions
Frequently Asked Questions
Who is G. Staley Cates and what is his relevant experience?
Cates was Vice Chairman of Southeastern Asset Management from 2015 through 2024 and served as its President from 1989 through 2015, after joining the firm in 1986. He holds a B.A. from the University of Texas at Austin and is a Chartered Financial Analyst. He also has extensive civic and philanthropic involvement in Memphis.
Why is Karen Alvingham leaving the Board?
The filing states that Alvingham notified the Company on February 22, 2026 of her decision to retire from the Board, effective April 1, 2026. No reason beyond the retirement decision was disclosed. She said in the press release that she was honored to have served over the past eight years.
Does Jay Horgen's re-appointment as President change his role?
Horgen will hold the title of President in addition to his continuing role as Chief Executive Officer, both effective April 1, 2026. The filing does not describe any change in his responsibilities or compensation.
Are there any conflicts of interest or related-party transactions involving Cates?
The company states that Cates and his immediate family members are not party to any related person transaction requiring disclosure under Item 404(a) of Regulation S-K. There are also no familial relationships with current directors or officers and no arrangements under which he was selected for the Board.
Does this filing include any financial results or guidance?
No. The 8-K covers only board appointments, a director retirement, and an executive re-appointment. The press release is furnished under Item 7.01 and does not include financial results, earnings guidance, or updated financial metrics beyond the December 31, 2025 AUM figure.
04—Continue