Sotera Health's three largest insider shareholders as of September 12, 2026 are Pincus Co. Warburg (Director, 19.10Mn shares), Investment Xi Llc Gtcr (Director, 12.74Mn shares), Investment Xi Llc Gtcr (Director, 12.74Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Michael B. Jr. Petras | Executive Chairman | 397,912 | 3,969,393 | 4,367,305 | 45.6% | 19 Aug, 2026 |
| 2 | Michael P Rutz | President Of Sterigenics | 1,265,033 | 0 | 1,265,033 | 13.2% | 11 Aug, 2026 |
| 3 | Alton Shader | Chief Executive Officer | 955,512 | 0 | 955,512 | 10.0% | 27 May, 2026 |
| 4 | Scott J. Leffler | Cfo And Treasurer | 738,649 | 0 | 738,649 | 7.7% | 04 Mar, 2022 |
| 5 | Alexander Dimitrief | Former Svp, Gc And Sec. | 632,021 | 0 | 632,021 | 6.6% | 02 Apr, 2026 |
| 6 | Jonathan M. Lyons | Sr. Vice President, Cfo | 629,480 | 0 | 629,480 | 6.6% | 07 Aug, 2026 |
| 7 | Ann R. Klee | Director | 140,926 | 0 | 140,926 | 1.5% | 27 May, 2026 |
| 8 | Ruoxi Chen | Director | 95,751 | 0 | 95,751 | 1.0% | 27 May, 2026 |
| 9 | Vincent K Petrella | Director | 95,751 | 0 | 95,751 | 1.0% | 27 May, 2026 |
| 10 | James Neary | Director | 95,751 | 0 | 95,751 | 1.0% | 27 May, 2026 |
| 11 | Sean Laurence Cunningham | Director | 95,751 | 0 | 95,751 | 1.0% | 27 May, 2026 |
| 12 | David E. Wheadon | Director | 89,882 | 0 | 89,882 | 0.9% | 27 May, 2026 |
| 13 | Constantine S Mihas | Director | 80,781 | 0 | 80,781 | 0.8% | 27 May, 2025 |
| 14 | David Donnini | Director | 61,649 | 0 | 61,649 | 0.6% | 29 May, 2024 |
| 15 | Robert Brown Knauss | Director | 54,933 | 0 | 54,933 | 0.6% | 27 May, 2025 |
| 16 | Karen Flynn | Director | 54,191 | 0 | 54,191 | 0.6% | 27 May, 2026 |
| 17 | Christopher Simon, | Director | 34,102 | 0 | 34,102 | 0.4% | 27 May, 2026 |
| 18 | Terry Hammons | Svp, Gc And Secretary | 31,257 | 0 | 31,257 | 0.3% | 04 Mar, 2022 |
| 19 | Stephanie Geveda | Director | 25,848 | 0 | 25,848 | 0.3% | 31 May, 2022 |
| 20 | Kenneth D. Krause | Director | 14,970 | 0 | 14,970 | 0.2% | 27 May, 2026 |
| 21 | Richard G Kyle | Director | 14,970 | 0 | 14,970 | 0.2% | 27 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 |
|---|---|---|---|---|---|---|---|---|
| 17 Aug, 2026 | Michael B. Jr. Petras | Executive Chairman | Disposed S | 294,515 | $18.50 | $5.45Mn | 397,912 | Direct |
| 17 Aug, 2026 | Michael B. Jr. Petras | Executive Chairman | Disposed S | 850,000 | $18.50 | $15.73Mn | 3,969,393 | Indirect |
| 07 Aug, 2026 | Michael P Rutz | President Of Sterigenics | Disposed S | 150,000 | $18.84 | $2.83Mn | 334,279 | Direct |
| 05 Aug, 2026 | Jonathan M. Lyons | Sr. Vice President, Cfo | Disposed F | 11,316 | $17.98 | $203.46K | 217,304 | Direct |
| 22 May, 2026 | Kenneth D. Krause | Director | Acquired A | 14,970 | $0.00 | $0 | 14,970 | Direct |
| 22 May, 2026 | James Neary | Director | Acquired A | 14,970 | $0.00 | $0 | 95,751 | Direct |
| 22 May, 2026 | Vincent K Petrella | Director | Acquired A | 14,970 | $0.00 | $0 | 95,751 | Direct |
| 22 May, 2026 | David E. Wheadon | Director | Acquired A | 14,970 | $0.00 | $0 | 89,882 | Direct |
| 22 May, 2026 | Karen Flynn | Director | Acquired A | 14,970 | $0.00 | $0 | 54,191 | Direct |
| 22 May, 2026 | Ann R. Klee | Director | Acquired A | 14,970 | $0.00 | $0 | 140,926 | Direct |
| 26 May, 2026 | Alton Shader | Chief Executive Officer | Acquired A | 375,939 | $0.00 | $0 | 375,939 | Direct |
| 22 May, 2026 | Ruoxi Chen | Director | Acquired A | 14,970 | $0.00 | $0 | 95,751 | Direct |
| 22 May, 2026 | Sean Laurence Cunningham | Director | Acquired A | 14,970 | $0.00 | $0 | 95,751 | Direct |
| 22 May, 2026 | Richard G Kyle | Director | Acquired A | 14,970 | $0.00 | $0 | 14,970 | Direct |
| 22 May, 2026 | Christopher Simon, | Director | Acquired A | 14,970 | $0.00 | $0 | 34,102 | Direct |
| 26 May, 2026 | Alton Shader | Chief Executive Officer | Acquired A | 203,634 | $0.00 | $0 | 579,573 | Direct |
| 26 May, 2026 | Alton Shader | Chief Executive Officer | Acquired A | 101,817 | $0.00 | $0 | 101,817 | Direct |
| 13 May, 2026 | Investment Xi Llc Gtcr | Director, TenPercentOwner | Disposed S | 12,735,301 | $15.17 | $193.17Mn | 0 | Indirect |
| 13 May, 2026 | Pincus Co. Warburg | Director, TenPercentOwner | Disposed S | 19,102,952 | $15.17 | $289.75Mn | 0 | Indirect |
| 13 May, 2026 | Pincus Co. Warburg | Director, TenPercentOwner | Disposed S | 19,102,952 | $15.17 | $289.75Mn | 0 | Indirect |