As of September 09, 2026, Stagwell's top three insider holders are Mark Jeffery Penn (Chief Executive Officer, 23.03Mn shares), Mark Jeffery Penn (Chief Executive Officer, 22.30Mn shares), Bradley J. Gross (Director, 20.96Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Mark Jeffery Penn | Chief Executive Officer | 23,034,990 | 0 | 23,034,990 | 55.4% | 11 Aug, 2026 |
| 2 | Sachs Group Inc Goldman | TenPercentOwner | 0 | 12,981,022 | 12,981,022 | 31.2% | 17 Jun, 2024 |
| 3 | Jay Leveton | President | 2,009,454 | 0 | 2,009,454 | 4.8% | 03 Apr, 2026 |
| 4 | Ryan Greene | Chief Financial Officer | 1,391,279 | 0 | 1,391,279 | 3.3% | 03 Apr, 2026 |
| 5 | Frank P Lanuto | Evp, Finance | 491,977 | 0 | 491,977 | 1.2% | 04 Aug, 2026 |
| 6 | Charlene Barshefsky | Director | 238,286 | 0 | 238,286 | 0.6% | 12 Jun, 2026 |
| 7 | Irwin D Simon | Director | 228,891 | 0 | 228,891 | 0.6% | 12 Jun, 2026 |
| 8 | Brandt A. Vaughan | Director | 220,504 | 0 | 220,504 | 0.5% | 02 Jul, 2026 |
| 9 | Desiree G Rogers | Director | 214,984 | 0 | 214,984 | 0.5% | 12 Jun, 2026 |
| 10 | Wade Oosterman | Director | 180,966 | 0 | 180,966 | 0.4% | 16 Jun, 2025 |
| 11 | Eli Samaha | Director | 170,764 | 0 | 170,764 | 0.4% | 02 Jul, 2026 |
| 12 | Vincenzo Dimaggio | Svp, Chief Accounting Officer | 165,945 | 0 | 165,945 | 0.4% | 02 Apr, 2025 |
| 13 | Peter Mcelligott | General Counsel | 122,185 | 0 | 122,185 | 0.3% | 03 Apr, 2026 |
| 14 | Rodney E Slater | Director | 117,710 | 0 | 117,710 | 0.3% | 16 Jun, 2025 |
| 15 | Beth J Kaplan | Director | 15,459 | 0 | 15,459 | 0.0% | 13 Aug, 2026 |
| 16 | Bradley J. Gross | Director | 0 | 8,789 | 8,789 | 0.0% | 05 May, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 11 Aug, 2026 | Beth J Kaplan | Director | Acquired A | 15,459 | $0.00 | $0 | 15,459 | Direct |
| 09 Aug, 2026 | Mark Jeffery Penn | Chief Executive Officer | Acquired M | 500,000 | $8.27 | $4.14Mn | 23,534,990 | Direct |
| 09 Aug, 2026 | Mark Jeffery Penn | Chief Executive Officer | Disposed D | 500,000 | $9.17 | $4.59Mn | 23,034,990 | Direct |
| 09 Aug, 2026 | Mark Jeffery Penn | Chief Executive Officer | Acquired M | 75,000 | $6.79 | $509.25K | 23,109,990 | Direct |
| 09 Aug, 2026 | Mark Jeffery Penn | Chief Executive Officer | Disposed D | 75,000 | $9.17 | $687.75K | 23,034,990 | Direct |
| 09 Aug, 2026 | Mark Jeffery Penn | Chief Executive Officer | Disposed M | 500,000 | $0.00 | $0 | 1,000,000 | Direct |
| 09 Aug, 2026 | Mark Jeffery Penn | Chief Executive Officer | Disposed M | 75,000 | $0.00 | $0 | 150,000 | Direct |
| 31 Jul, 2026 | Frank P Lanuto | Officer | Disposed S | 62,000 | $8.46 | $524.52K | 491,977 | Direct |
| 01 Aug, 2026 | Mark Jeffery Penn | Chief Executive Officer | Acquired A | 2,000,000 | $0.00 | $0 | 2,000,000 | Direct |
| 01 Jul, 2026 | Eli Samaha | Director | Acquired A | 2,691 | $7.43 | $19.99K | 170,764 | Direct |
| 01 Jul, 2026 | Brandt A. Vaughan | Director | Acquired A | 2,355 | $7.43 | $17.50K | 220,504 | Direct |
| 11 Jun, 2026 | Charlene Barshefsky | Director | Acquired A | 22,970 | $0.00 | $0 | 238,286 | Direct |
| 11 Jun, 2026 | Irwin D Simon | Director | Acquired A | 22,970 | $0.00 | $0 | 228,891 | Direct |
| 11 Jun, 2026 | Brandt A. Vaughan | Director | Acquired A | 22,970 | $0.00 | $0 | 218,149 | Direct |
| 11 Jun, 2026 | Eli Samaha | Director | Acquired A | 22,970 | $0.00 | $0 | 168,073 | Direct |
| 11 Jun, 2026 | Desiree G Rogers | Director | Acquired A | 22,970 | $0.00 | $0 | 214,984 | Direct |
| 11 Jun, 2026 | Wade Oosterman | Director | Acquired A | 22,970 | $0.00 | $0 | 203,936 | Direct |
| 13 May, 2026 | Mark Jeffery Penn | Chief Executive Officer | Acquired P | 20,000 | $5.88 | $117.60K | 23,034,990 | Direct |
| 04 May, 2026 | Bradley J. Gross | Director | Disposed S | 2,163,790 | $6.04 | $13.07Mn | 8,789 | Indirect |
| 01 Apr, 2026 | Frank P Lanuto | Evp, Finance | Acquired A | 74,189 | $0.00 | $0 | 553,977 | Direct |