WLK's three largest insider shareholders as of May 30, 2026 are Albert Chao (Executive Chairman, 642.88K shares), L. Benjamin Ederington (Evp, Legal External Affairs, 80.16K shares), Dorothy C Jenkins (Director, 73.78K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Mark A Mccollum | - | 9,656 | 0 | 11 Aug, 2025 |
| Roger A Cregg | - | 1,339 | 0 | 10 Dec, 2025 |
| Albert Chao | Executive Chairman | 642,880 | 0 | 23 Feb, 2026 |
| Dorothy C Jenkins | - | 73,778 | 0 | 15 Aug, 2022 |
| James Chao | Senior Chairman | 49,774 | 0 | 23 Feb, 2026 |
| R Bruce Northcutt | - | 21,183 | 0 | 11 Aug, 2025 |
| Mark Steven Bender | Evp Cfo | 28,015 | 0 | 30 Mar, 2026 |
| Andrew Kenner | Svp, Operations | 20,362 | 0 | 22 Feb, 2022 |
| Jeffrey Wayne Sheets | - | 12,759 | 0 | 11 Aug, 2025 |
| Kimberly S Lubel | - | 11,653 | 0 | 11 Aug, 2025 |
| Michael J Graff | - | 21,142 | 0 | 11 Aug, 2025 |
| Robert F. Buesinger | Evp, Pem Segment Head | 34,482 | 0 | 31 Mar, 2026 |
| Marius Haas | - | 11,631 | 0 | 12 Aug, 2024 |
| L. Benjamin Ederington | Evp, Legal External Affairs | 80,158 | 0 | 23 Feb, 2026 |
| David Tsung-Hung Chao | - | 0 | 19,423 | 01 Sep, 2023 |
| Roger L. Kearns | Coo And Evp, Pem | 39,849 | 0 | 15 Mar, 2023 |
| John Tsung-Chen Chao | - | 7,888 | 0 | 23 Feb, 2026 |
| Johnathan Stevan Zoeller | Vp And Cao | 4,416 | 0 | 22 Mar, 2024 |
| Thomas J. Janssens | Svp, Ops Pem Corp Logistic | 17,127 | 0 | 24 Feb, 2025 |
| Carolyn Chao Sabat | - | 3,580 | 0 | 11 Aug, 2025 |
| Catherine T. Chao | - | 0 | 19,423 | 01 Sep, 2023 |
| Jeffrey Adam Holy | Vp And Cao | 5,124 | 0 | 23 Feb, 2026 |
| Scott Thomas Szwejbka | Svp, Hip Segment Head | 13,773 | 0 | 23 Feb, 2026 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 02 Apr, 2026 | Brian John Powers | Restricted Stock Units | A | 1,961 | $0.00 | 1,961 | D | A |
| 02 Apr, 2026 | Brian John Powers | Restricted Stock Units | A | 1,961 | $0.00 | 1,961 | D | A |
| 27 Mar, 2026 | Robert F. Buesinger | Common Stock | D | 4,000 | $115.25 | 34,482 | D | S |
| 27 Mar, 2026 | Mark Steven Bender | Common Stock | D | 16,413 | $112.54 | 28,015 | D | S |
| 27 Feb, 2026 | Mark Steven Bender | Common Stock | A | 6,199 | $65.81 | 68,041 | D | M |
| 27 Feb, 2026 | Mark Steven Bender | Common Stock | A | 6,494 | $86.54 | 74,535 | D | M |
| 27 Feb, 2026 | Mark Steven Bender | Common Stock | D | 12,693 | $98.20 | 61,842 | D | D |
| 27 Feb, 2026 | Mark Steven Bender | Common Stock | D | 16,988 | $100.91 | 44,854 | D | S |
| 27 Feb, 2026 | Mark Steven Bender | Common Stock | D | 421 | $101.52 | 44,433 | D | S |
| 27 Feb, 2026 | Mark Steven Bender | Employee Option (right to buy) | D | 6,199 | $0.00 | 0 | D | M |
| 27 Feb, 2026 | Mark Steven Bender | Employee Option (right to buy) | D | 6,494 | $0.00 | 0 | D | M |
| 20 Feb, 2026 | Bhavesh V. Patel | Restricted Stock Units | A | 1,852 | $0.00 | 1,852 | D | A |
| 19 Feb, 2026 | L. Benjamin Ederington | Common Stock | A | 1,425 | $0.00 | 80,515 | D | A |
| 19 Feb, 2026 | Mark Steven Bender | Common Stock | A | 1,777 | $0.00 | 62,287 | D | A |
| 19 Feb, 2026 | Scott Thomas Szwejbka | Common Stock | A | 365 | $0.00 | 13,864 | D | A |
| 19 Feb, 2026 | James Chao | Common Stock | A | 3,884 | $0.00 | 51,343 | D | A |
| 19 Feb, 2026 | Robert F. Buesinger | Common Stock | A | 1,301 | $0.00 | 38,808 | D | A |
| 19 Feb, 2026 | John Tsung-Chen Chao | Common Stock | A | 213 | $0.00 | 7,979 | D | A |
| 19 Feb, 2026 | Albert Chao | Common Stock | A | 6,193 | $0.00 | 645,381 | D | A |
| 19 Feb, 2026 | Jeffrey Adam Holy | Common Stock | A | 264 | $0.00 | 5,205 | D | A |