Trinseo's three largest insider shareholders as of September 29, 2026 are Investment Management Ltd Mg (TenPercentOwner, 7.63Mn shares), Investment Management Ltd Mg (TenPercentOwner, 7.63Mn shares), Frank A Bozich (Ceo And President, 664.69K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Investment Management Ltd Mg | TenPercentOwner | 0 | 7,625,044 | 7,625,044 | 74.6% | 20 Jul, 2022 |
| 2 | Frank A Bozich | Ceo And President | 664,689 | 0 | 664,689 | 6.5% | 03 Mar, 2026 |
| 3 | Angelo N. Chaclas | Svp, Clo, Cco Corp. Sec. | 274,798 | 0 | 274,798 | 2.7% | 03 Mar, 2026 |
| 4 | David Phillip Stasse | Evp And Cfo | 254,788 | 0 | 254,788 | 2.5% | 03 Mar, 2026 |
| 5 | Matthew Farrell | Director | 207,741 | 0 | 207,741 | 2.0% | 14 May, 2026 |
| 6 | Francesca Reverberi | Svp, Em And Polymer Solutions | 161,250 | 0 | 161,250 | 1.6% | 03 Mar, 2026 |
| 7 | Paula M. Cooney | Svp, Chro | 118,318 | 0 | 118,318 | 1.2% | 03 Mar, 2026 |
| 8 | Rainer Schewe | Svp, Supply Chain Mfg Svcs | 103,415 | 0 | 103,415 | 1.0% | 03 Mar, 2026 |
| 9 | Kessel Bregje Van | Svp, Corporate Finance Ir | 98,296 | 0 | 98,296 | 1.0% | 03 Mar, 2026 |
| 10 | Han Hendriks | Svp, Chief Technology Officer | 73,362 | 0 | 73,362 | 0.7% | 03 Mar, 2026 |
| 11 | Henri Steinmetz | Director | 53,453 | 0 | 53,453 | 0.5% | 14 May, 2026 |
| 12 | Joseph Alvarado | Director | 52,187 | 0 | 52,187 | 0.5% | 14 May, 2026 |
| 13 | Arthas Bing Yang | Svp, Latex Binders | 49,457 | 0 | 49,457 | 0.5% | 03 Mar, 2026 |
| 14 | Klynne Johnson | Director | 48,429 | 0 | 48,429 | 0.5% | 14 May, 2026 |
| 15 | Jeanmarie F. Desmond | Director | 46,552 | 0 | 46,552 | 0.5% | 14 May, 2026 |
| 16 | Jeffrey J Cote | Director | 45,699 | 0 | 45,699 | 0.4% | 14 May, 2026 |
| 17 | Roger Greene | Vp, Global Controller Pao | 45,101 | 0 | 45,101 | 0.4% | 03 Mar, 2026 |
| 18 | Sandra Beach Lin | Director | 44,776 | 0 | 44,776 | 0.4% | 14 May, 2026 |
| 19 | Victoria Brifo | Director | 40,741 | 0 | 40,741 | 0.4% | 14 May, 2026 |
| 20 | Mark E Tomkins | Director | 36,619 | 0 | 36,619 | 0.4% | 24 Jun, 2025 |
| 21 | Leener Pierre-Marie De | Director | 36,174 | 0 | 36,174 | 0.4% | 24 Jun, 2025 |
| 22 | Nicolas Joly | Svp, Styrenics | 25,984 | 0 | 25,984 | 0.3% | 28 Feb, 2023 |
| 23 | Donald T Misheff | Director | 19,654 | 0 | 19,654 | 0.2% | 13 Jul, 2023 |
| 24 | Andre Lanning | Svp Cco | 18,145 | 0 | 18,145 | 0.2% | 28 Feb, 2023 |
| 25 | Timothy J Thomas | Svp, Mfctg Oper Excellence | 17,737 | 0 | 17,737 | 0.2% | 21 Feb, 2024 |
| 26 | Johanna Frisch | Vp And Treasurer | 15,898 | 0 | 15,898 | 0.2% | 02 Oct, 2025 |
| 27 | Bernard M Skeete | Vp, Cao Global Controller | 12,822 | 0 | 12,822 | 0.1% | 28 Feb, 2023 |
| 28 | Alice Heezen | Svp Human Resources | 10,081 | 0 | 10,081 | 0.1% | 16 Nov, 2021 |
| 29 | Philip R Martens | Director | 9,414 | 0 | 9,414 | 0.1% | 13 Jul, 2023 |
| 30 | Jean-Luc Beal | Svp, Engineered Materials | 9,254 | 0 | 9,254 | 0.1% | 24 Feb, 2023 |
| 31 | James Mingyu Ni | Svp, Latex Binders | 6,904 | 0 | 6,904 | 0.1% | 21 Feb, 2024 |
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 |
|---|---|---|---|---|---|---|---|---|
| 12 May, 2026 | Sandra Beach Lin | Director | Disposed J | 42,484 | — | — | 44,776 | Direct |
| 12 May, 2026 | Klynne Johnson | Director | Disposed J | 42,484 | — | — | 48,429 | Direct |
| 12 May, 2026 | Jeffrey J Cote | Director | Disposed J | 42,484 | — | — | 45,699 | Direct |
| 12 May, 2026 | Jeanmarie F. Desmond | Director | Disposed J | 42,484 | — | — | 46,552 | Direct |
| 12 May, 2026 | Victoria Brifo | Director | Disposed J | 42,484 | — | — | 40,741 | Direct |
| 12 May, 2026 | Matthew Farrell | Director | Disposed J | 42,484 | — | — | 207,741 | Direct |
| 12 May, 2026 | Joseph Alvarado | Director | Disposed J | 42,484 | — | — | 52,187 | Direct |
| 12 May, 2026 | Henri Steinmetz | Director | Disposed J | 42,484 | — | — | 53,453 | Direct |
| 27 Feb, 2026 | Rainer Schewe | Svp, Supply Chain Mfg Svcs | Disposed F | 4,028 | $0.23 | $926 | 103,415 | Direct |
| 27 Feb, 2026 | Frank A Bozich | Ceo And President | Disposed F | 23,680 | $0.23 | $5.45K | 664,689 | Direct |
| 27 Feb, 2026 | Angelo N. Chaclas | Svp, Clo, Cco Corp. Sec. | Disposed F | 7,607 | $0.23 | $1.75K | 274,798 | Direct |
| 27 Feb, 2026 | Kessel Bregje Van | Svp, Corporate Finance Ir | Disposed F | 6,064 | $0.23 | $1.39K | 98,296 | Direct |
| 27 Feb, 2026 | David Phillip Stasse | Evp And Cfo | Disposed F | 10,366 | $0.23 | $2.38K | 254,788 | Direct |
| 27 Feb, 2026 | Paula M. Cooney | Svp, Chro | Disposed F | 7,670 | $0.23 | $1.76K | 118,318 | Direct |
| 27 Feb, 2026 | Francesca Reverberi | Svp, Em And Polymer Solutions | Disposed F | 1,385 | $0.23 | $319 | 161,250 | Direct |
| 27 Feb, 2026 | Han Hendriks | Svp, Chief Technology Officer | Disposed F | 7,707 | $0.23 | $1.77K | 73,362 | Direct |
| 27 Feb, 2026 | Arthas Bing Yang | Svp, Latex Binders | Disposed F | 2,548 | $0.23 | $586 | 49,457 | Direct |
| 27 Feb, 2026 | Roger Greene | Vp, Global Controller Pao | Disposed F | 2,517 | $0.23 | $579 | 45,101 | Direct |
| 21 Feb, 2026 | Kessel Bregje Van | Svp, Corporate Finance Ir | Disposed F | 5,963 | $0.33 | $1.95K | 105,695 | Direct |
| 21 Feb, 2026 | David Phillip Stasse | Evp And Cfo | Disposed F | 5,028 | $0.33 | $1.65K | 274,825 | Direct |