Westlake Corporation
US ˙ NYSE ˙ US9604131022

SecurityWLK / Westlake Corporation
InstitutionEngineers Gate Manager LP
Latest Disclosed Ownership42,499 shares
Latest Disclosed Value $ 4,964,733
Engineers Gate Manager LP reports 85.31% decrease in ownership of WLK / Westlake Corporation

On May 15, 2026 - Engineers Gate Manager LP filed a 13F-HR form disclosing ownership of 42,499 shares of Westlake Corporation (US:WLK) valued at $4,964,733 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 289,255 shares of Westlake Corporation. This represents a change in shares of -85.31% during the quarter. The current value of the position is $3,671,489 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F WESTLAKE COM 960413102 42,499 -246,756 -85.31 4,965 -76.79 0.0621
2026-02-17 2025-12-31 13F WESTLAKE COM 960413102 289,255 289,255 21,388 0.2536
2025-11-14 2025-09-30 13F WESTLAKE COM 960413102 0 -351,011 -100.00 0 -100.00
2025-08-14 2025-06-30 13F WESTLAKE COM 960413102 351,011 348,274 12,724.66 26,652 9,662.64 0.3316
2025-05-15 2025-03-31 13F WESTLAKE COM 960413102 2,737 138 5.31 274 -8.08 0.0046
2025-02-14 2024-12-31 13F WESTLAKE COM 960413102 2,599 -20,050 -88.52 298 -91.27 0.0052
2024-11-14 2024-09-30 13F WESTLAKE COM 960413102 22,649 14,873 191.27 3,404 202.22 0.0664
2024-08-14 2024-06-30 13F WESTLAKE COM 960413102 7,776 7,776 1,126 0.0254
2024-02-14 2023-12-31 13F WESTLAKE COM 960413102 0 -3,588 -100.00 0 -100.00
2023-11-14 2023-09-30 13F WESTLAKE COM 960413102 3,588 3,588 447 0.0165
2023-02-14 2022-12-31 13F WESTLAKE COM 960413102 0 -4,500 -100.00 0 -100.00
2022-11-14 2022-09-30 13F WESTLAKE COM 960413102 4,500 -6,740 -59.96 391 -64.52 0.0243
2022-08-15 2022-06-30 13F WESTLAKE COM 960413102 11,240 7,651 213.18 1,102 148.76 0.0404
2022-05-16 2022-03-31 13F WESTLAKE COM 960413102 3,589 -4,621 -56.29 443 -44.42 0.0173
2022-02-14 2021-12-31 13F WESTLAKE CHEM COM 960413102 8,210 3,280 66.53 797 77.51 0.0358
2021-11-15 2021-09-30 13F WESTLAKE CHEM COM 960413102 4,930 -18,369 -78.84 449 -78.61 0.0256
2021-08-16 2021-06-30 13F WESTLAKE CHEM COM 960413102 23,299 19,099 454.74 2,099 462.73 0.1350
2021-05-17 2021-03-31 13F WESTLAKE CHEM COM 960413102 4,200 1,370 48.41 373 61.47 0.0185
2021-02-16 2020-12-31 13F WESTLAKE CHEM COM 960413102 2,830 -4,873 -63.26 231 -52.57 0.0100
2020-11-16 2020-09-30 13F WESTLAKE CHEM COM 960413102 7,703 7,703 487 0.0229
2019-02-14 2018-12-31 13F WESTLAKE CHEM COM 960413102 0 -27,855 -100.00 0 -100.00
2018-11-01 2018-09-30 13F WESTLAKE CHEM COM 960413102 27,855 27,855 2,315 0.1779
2018-08-03 2018-06-30 13F WESTLAKE CHEM COM 960413102 0 -12,530 -100.00 0 -100.00
2018-05-07 2018-03-31 13F WESTLAKE CHEM COM 960413102 12,530 -31,470 -71.52 1,393 -70.28 0.0928
2018-02-01 2017-12-31 13F WESTLAKE CHEM COM 960413102 44,000 44,000 4,687 0.3217
2017-11-13 2017-09-30 13F WESTLAKE CHEM COM 960413102 0 -3,306 -100.00 0 -100.00
2017-08-10 2017-06-30 13F WESTLAKE CHEM COM 960413102 3,306 3,306 219 0.0197
2016-08-11 2016-06-30 13F WESTLAKE CHEM COM 960413102 0 -87,221 -100.00 0 -100.00
2016-05-09 2016-03-31 13F WESTLAKE CHEM COM 960413102 87,221 75,674 655.36 4,038 544.02 0.3148
2016-02-05 2015-12-31 13F WESTLAKE CHEM COM 960413102 11,547 -51,445 -81.67 627 -80.82 0.0423
2015-11-16 2015-09-30 13F WESTLAKE CHEM COM 960413102 62,992 55,431 733.12 3,269 529.87 0.2784
2015-08-14 2015-06-30 13F WESTLAKE CHEM COM 960413102 7,561 -756 -9.09 519 -13.21 0.0508
2015-05-15 2015-03-31 13F WESTLAKE CHEM COM 960413102 8,317 8,317 598 0.0795
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.