Westlake WLK Insider Ownership

Updated Oct 10, 2026

Over the past year, WLK insiders sold $10.19 million of stock (117.53K shares) on the open market and bought none.

• Behind Westlake's open-market sales in the past 12 months were 3 insiders, and no insider bought.
• Albert Chao (Executive Chairman) was WLK's largest open-market seller in the past 12 months, with $6.13 million of sales (79.71K shares); the latest was on August 11, 2026.
• In transactions other than open-market trades, Westlake insiders received 15.42K shares in stock awards, acquired 191.14K shares through option exercises and conversions and gave up 22.25K shares to cover taxes or exercise prices over the past 12 months.
• Per Business Quant, WLK insiders together hold 1.02Mn shares based on their latest Form 4 filings, up 0.78% from 1.01Mn shares at the end of Q2 2026 and up 7.19% from 953.33K shares at the end of Q3 2025.
• Indirect holdings, through trusts, partnerships, family members and other entities, make up 1.90% (19.42K shares) of Westlake's insider total, with the other 98.10% (1Mn shares) held directly.
• Holdings in Westlake stock are reported by 18 insiders, the officers, directors and 10% owners who have filed a Form 4 in the past two years.
• Westlake's three largest insider shareholders, based on their latest Form 4 filings, are Albert Chao (Executive Chairman, 642.88K shares), L. Benjamin Ederington (EVP, Legal & External Affairs, 80.16K shares) and James Chao (Senior Chairman, 49.77K shares).
• Albert Chao alone accounts for 62.91% of the shares held by Westlake insiders.
• Institutions held 31.04% of Westlake's outstanding shares in their Q2 2026 13F filings, insiders about 0.80% based on their latest Form 4 filings, and other investors, including the public, the remaining 68.16%.
• Over the past 12 months, 22 insiders reported transactions in Westlake stock in 47 Form 4 filings.
• Insider figures for WLK include Form 4 filings through September 1, 2026.