WLK (Westlake Corporation)
Insider Trading Activity
Every open-market purchase and sale reported by WLK officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-17 | MARK A MCCOLLUM | Director | A | — | — |
| 2026-08-17 | David Tsung-Hung Chao | Director | A | — | — |
| 2026-08-17 | Bhavesh V. Patel | Director | A | — | — |
| 2026-08-17 | Carolyn Chao Sabat | Director | A | — | — |
| 2026-08-17 | ROGER A CREGG | Director | A | — | — |
| 2026-08-17 | Michael J Graff | Director | A | — | — |
| 2026-08-17 | Kimberly S Lubel | Director | A | — | — |
| 2026-08-17 | Jeffrey Wayne Sheets | Director | A | — | — |
| 2026-08-17 | Catherine T. Chao | Director | A | — | — |
| 2026-08-17 | R BRUCE NORTHCUTT | Director | A | — | — |
| 2026-08-11 | Albert Chao | Executive Chairman | MIXED | — | — |
| 2026-08-10 | Carolyn Chao Sabat | Director | M | — | — |
| 2026-08-10 | Michael J Graff | Director | M | — | — |
| 2026-08-10 | David Tsung-Hung Chao | Director | M | — | — |
| 2026-08-10 | ROGER A CREGG | Director | M | — | — |
| 2026-08-10 | Kimberly S Lubel | Director | M | — | — |
| 2026-08-10 | Jeffrey Wayne Sheets | Director | M | — | — |
| 2026-08-10 | Catherine T. Chao | Director | M | — | — |
| 2026-08-10 | MARK A MCCOLLUM | Director | M | — | — |
| 2026-08-10 | R BRUCE NORTHCUTT | Director | M | — | — |
| 2026-06-16 | Jonathan Baksht | SVP and CFO | A | — | — |
| 2026-05-14 | Mark Steven Bender | EVP & CFO | MIXED | — | — |
| 2026-04-06 | Brian John Powers | SVP, PEM Segment Head | A | — | — |
| 2026-03-31 | Robert F. Buesinger | EVP, PEM Segment Head | Sell | — | — |
| 2026-03-30 | Mark Steven Bender | EVP & CFO | Sell | — | — |
| 2026-03-06 | Mark Steven Bender | EVP & CFO | F | — | — |
| 2026-03-02 | Mark Steven Bender | EVP & CFO | MIXED | — | — |
| 2026-02-24 | Bhavesh V. Patel | Director | A | — | — |
| 2026-02-23 | James Chao | Senior Chairman | MIXED | — | — |
| 2026-02-23 | Albert Chao | Executive Chairman | MIXED | — | — |
| 2026-02-23 | John Tsung-chen Chao | Director | MIXED | — | — |
| 2026-02-23 | Mark Steven Bender | EVP & CFO | MIXED | — | — |
| 2026-02-23 | Robert F. Buesinger | EVP, PEM Segment Head | MIXED | — | — |
| 2026-02-23 | L. Benjamin Ederington | EVP, Legal & External Affairs | MIXED | — | — |
| 2026-02-23 | Jean-Marc Gilson | President and CEO | A | — | — |
| 2026-02-23 | Jeffrey Adam Holy | VP and CAO | MIXED | — | — |
| 2026-02-23 | Scott Thomas Szwejbka | SVP, HIP Segment Head | MIXED | — | — |
| 2026-02-19 | Mark Steven Bender | EVP & CFO | MIXED | — | — |
| 2026-02-19 | Robert F. Buesinger | EVP, PEM Segment Head | MIXED | — | — |
| 2026-02-19 | Albert Chao | Executive Chairman | MIXED | — | — |
| 2026-02-19 | John Tsung-chen Chao | Director | MIXED | — | — |
| 2026-02-19 | James Chao | Senior Chairman | MIXED | — | — |
| 2026-02-19 | L. Benjamin Ederington | EVP, Legal & External Affairs | MIXED | — | — |
| 2026-02-19 | Jeffrey Adam Holy | VP and CAO | MIXED | — | — |
| 2026-02-19 | Scott Thomas Szwejbka | SVP, HIP Segment Head | MIXED | — | — |
| 2025-12-23 | Albert Chao | Executive Chairman | MIXED | — | — |
| 2025-12-10 | ROGER A CREGG | Director | M | — | — |
| 2025-10-03 | Scott Thomas Szwejbka | SVP, HIP Segment Head | MIXED | — | — |
| 2025-08-29 | James Chao | Senior Chairman | G | — | — |
| 2025-08-11 | Jeffrey Wayne Sheets | Director | M | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | Executive Chairman | 94,079,818 | — |
| — | Director | 93,479,332 | — |
| — | Senior Chairman | 93,455,328 | — |
| — | Director | 93,413,442 | — |
| — | Director | 93,411,302 | — |
| — | 10%+ Owner | 93,100,554 | — |
| — | EVP, Legal & External Affairs | 80,515 | — |
| — | Sr VP, Vinyls | 62,908 | — |
| — | VP, General Counsel, Secretary | 50,726 | — |
| — | Senior Vice President | 48,170 | — |
| — | COO and EVP, PEM | 40,148 | — |
| — | EVP & CFO | 35,895 | — |
| — | EVP, PEM Segment Head | 34,482 | — |
| — | Director | 30,503 | — |
| — | Sr VP, Polyethylene | 28,349 | — |
| — | Director | 27,171 | — |
| — | Sr VP, Corp Bus Dev | 26,212 | — |
| — | Sr VP Adminstration | 25,807 | — |
| — | Director | 23,351 | — |
| — | Director | 23,310 | — |
| — | Director | 22,918 | — |
| — | Director | 22,652 | — |
| — | EVP and Special Advisor to CEO | 21,726 | — |
| — | SVP, Operations | 20,362 | — |
| — | SVP, Ops - PEM & Corp Logistic | 17,733 | — |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the WLK quote page; the site-wide leaderboard is on the insider transactions hub.