| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Chao Albert | Executive Chairman, Director | 2801 POST OAK BLVD., STE. 600, HOUSTON | Albert Chao by J Feng POA | 23 Dec 2025 | 0001299403 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | WLK | Common Stock | Options Exercise | $3.63M | +81.7K | +13.92% | $44.42 | 669K | 22 Dec 2025 | Direct | |
| transaction | WLK | Common Stock | Sale | -$707K | -9.71K | -1.45% | $72.82 | 659K | 22 Dec 2025 | Direct | F1, F2 |
| transaction | WLK | Common Stock | Sale | -$2.26M | -30.6K | -4.65% | $73.80 | 628K | 22 Dec 2025 | Direct | F1, F3 |
| transaction | WLK | Common Stock | Sale | -$38.8K | -521 | -0.08% | $74.44 | 628K | 22 Dec 2025 | Direct | F1, F4 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Underlying Class | Amount | Exercise Price | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | WLK | Employee Option (right to buy) | Options Exercise | $0 | -81.7K | -100% | $0.00 | 0 | 22 Dec 2025 | Common Stock | 81.7K | $44.42 | Direct | F5 |
| Id | Content |
|---|---|
| F1 | A portion of the sale proceeds were used to cover the strike price and related taxes in regards to the excercise of the options disclosed in Table II. |
| F2 | Weighted average price. These shares were sold in multiple transactions ranging from $72.395 to $73.39 inclusive. The reporting person undertakes to provide the issuer, any security holder of the issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. |
| F3 | Weighted average price. These shares were sold in multiple transactions ranging from $73.40 to $74.40 inclusive. The reporting person undertakes to provide the issuer, any security holder of the issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. |
| F4 | Weighted average price. These shares were sold in multiple transactions ranging from $74.405 to $74.515 inclusive. The reporting person undertakes to provide the issuer, any security holder of the issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. |
| F5 | The stock options are exercisable in three installments of 33%, 33% and 34% on February 18, 2017, 2018 and 2019, respectively. |