Welcome to our dedicated page for WESTLAKE CORPORATION SEC filings (Ticker: WLK), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
The Westlake Corporation (NYSE: WLK) SEC filings page on Stock Titan provides direct access to the company’s regulatory disclosures, including current reports on Form 8-K and other key documents filed with the U.S. Securities and Exchange Commission. Westlake is a Houston-headquartered global manufacturer and supplier of materials and products serving housing and construction, packaging, healthcare, automotive and consumer goods, and its filings offer detailed insight into these activities.
Recent Form 8-K filings describe a range of material events. These include the announcement and completion of Westlake’s acquisition of the global compounding solutions businesses of the ACI/Perplastic Group, which expands Westlake Global Compounds’ presence in specialty materials for the wire and cable sectors and extends its manufacturing footprint into Portugal, Romania and Tunisia. Other 8-Ks outline an underwriting agreement and the issuance of senior notes due 2035 and 2055, the commencement and pricing of a cash tender offer for 3.600% senior notes due 2026, and the results of that tender offer.
Filings also cover operational decisions, such as an 8-K reporting a plan to cease operation of certain North American chlorovinyl production facilities and a styrene plant at Lake Charles, Louisiana, while continuing to supply PVC, VCM and chlor-alkali products from seven other North American chlorovinyl facilities. Additional 8-Ks furnish quarterly earnings press releases, investor presentations and dividend announcements.
On Stock Titan, these SEC filings are paired with AI-powered summaries that explain the core points of each document in plain language. Users can quickly understand the significance of a tender offer, a new debt issuance, an acquisition closing or a capacity rationalization without reading every page. The filings page updates as new documents are posted to EDGAR, helping investors follow Westlake’s material events, financing activities and strategic moves through its official disclosures.
Westlake Corporation (WLK) furnished a press release announcing its third‑quarter 2025 results. The company also scheduled a conference call on October 30, 2025 to discuss the quarter and made an investor presentation available. The materials were provided as Exhibit 99.1 (press release) and Exhibit 99.2 (investor presentation) and were furnished, not filed, under the Exchange Act.
Scott Szwejbka, SVP, HIP Segment Head at Westlake Corp (WLK), reported vesting and disposition activity in the company’s common stock. On 10/01/2025 10,840 restricted stock units (RSUs) vested and converted one-for-one into 10,840 shares of common stock, increasing his beneficial holdings to 16,659 shares. On 10/02/2025 a disposition of 3,842 shares occurred, listed as a sale at $76.70 per share, reducing his beneficial ownership to 12,817 shares; the filing explains these shares were withheld to satisfy tax obligations arising from the RSU vesting. The Form 4 was signed by power of attorney on 10/03/2025.
James Chao, Senior Chairman and Director of Westlake Corp (WLK), reported an insider disposition on Form 4. The filing shows a gift (Code G) of 15,140 shares on 08/28/2025 at a reported price of $0, leaving Mr. Chao with 39,741 shares beneficially owned after the transaction.
The Form 4 was signed by a power of attorney on 08/29/2025. No derivative transactions or additional details are reported.
Westlake Corporation reported that on August 26, 2025 it entered into an agreement to acquire the global compounding solutions businesses of the ACI/Perplastic Group. The company disclosed this agreement through a Regulation FD communication, indicating it views the transaction as important information for the market. Details of the deal terms and strategic rationale are described in a press release furnished as Exhibit 99.1 to the report.
The press release and related disclosure are furnished rather than filed, which limits their use for certain liability purposes under U.S. securities laws unless later specifically incorporated into other company filings.
Michael J. Graff, a director of Westlake Corporation (WLK), filed a Form 4 reporting restricted stock unit activity and resulting ownership. The filing shows an acquisition on 08/08/2025 of 2,168 restricted stock units and a related transaction on 08/09/2025 affecting 1,128 restricted stock units. The document states restricted stock units convert into common stock one-for-one and that all restricted stock units will vest on August 8, 2026. The report lists a beneficial ownership of 21,142 common shares following the reported transactions. The form is signed by Michael Graff by POA on 08/11/2025.
Westlake Corporation (WLK) director Catherine T. Chao reported restricted stock unit activity and changes in beneficial ownership. The filing shows acquisitions or grant-related entries dated 08/08/2025 and 08/09/2025, including 2,168 restricted stock units on 08/08/2025 and a separate 1,128 restricted stock unit transaction on 08/09/2025. The filing states restricted stock units convert one-for-one into common stock and that all of the 2,168 units will vest on August 8, 2026. An earlier grant of 1,128 RSUs was made on August 9, 2024 and vests on its first anniversary.
The report also shows beneficial ownership following the reported transactions of 5,580 shares held directly and 19,423 shares held indirectly in a trust for the reporting person, who serves as sole trustee. Explanations in the filing describe the trust and the one-for-one conversion feature of the RSUs.
David Tsung-Hung Chao, a director of Westlake Corp (WLK), reported changes in his equity holdings. The filing shows direct beneficial ownership of 8,912 shares and indirect beneficial ownership of 19,423 shares held in a trust for which he serves as sole trustee. The filing records restricted stock units (RSUs): 2,168 RSUs were acquired on 08/08/2025 and 1,128 RSUs were modified on 08/09/2025. RSUs convert one-for-one into common stock and, per the filing, all RSUs will vest on 08/08/2026; the 1,128 RSUs were originally granted on 08/09/2024 and vest on their first anniversary.
R. Bruce Northcutt, a director of Westlake Corporation (WLK), reported stock-unit activity on the issuer's Form 4. The Form records activity on 08/08/2025 and 08/09/2025 consisting of restricted stock units and common-stock entries that affect his holdings.
The filing shows 2,168 restricted stock units reported on 08/08/2025 and an additional 1,128 common-stock units reported on 08/09/2025. The restricted stock units convert one-for-one into common stock and are disclosed to vest on August 8, 2026. Following the reported transactions the form shows the reporting person directly beneficially owns 21,183 shares of Westlake common stock. One grant of 1,128 restricted stock units was originally granted on August 9, 2024 and noted as vesting on its first anniversary.
Westlake Corporation (WLK) insider filing shows director Carolyn C. Sabat reported equity award activity on Form 4. The filing records restricted stock unit (RSU) transactions dated 08/08/2025 and 08/09/2025. The RSUs convert into common stock on a one-for-one basis and all RSUs will vest on August 8, 2026. The filing lists an acquisition of 2,168 RSUs on 08/08/2025 and a transaction involving 1,128 RSUs on 08/09/2025, with the entries showing the number of underlying common shares associated with each RSU line.
The reporting person is identified as a director of the issuer. The form is signed by Carolyn C. Sabat by POA J Feng and dated 08/11/2025. The document provides specific grant, conversion, and vesting details but does not include additional context such as exercise prices beyond $0 for the RSUs or the economic rationale for the transactions.
Mark A. McCollum, a director of Westlake Corporation (WLK), converted previously granted restricted stock units into common shares and received a new grant of restricted stock units. On 08/09/2025, 1,128 restricted stock units that had been granted on 08/09/2024 vested and converted one-for-one into 1,128 shares of common stock. After that conversion his reported beneficial ownership of common stock was 9,656 shares.
Separately, on 08/08/2025 he was awarded 2,168 restricted stock units that will vest on 08/08/2026 and convert one-for-one into common shares when they vest. The filing identifies him as a director and shows the holdings as direct beneficial ownership.