Westlake Corporation
US ˙ NYSE ˙ US9604131022

SecurityWLK / Westlake Corporation
InstitutionQuantbot Technologies LP
Latest Disclosed Ownership23,936 shares
Latest Disclosed Value $ 2,796,204
Quantbot Technologies LP reports 39.57% decrease in ownership of WLK / Westlake Corporation

On May 13, 2026 - Quantbot Technologies LP filed a 13F-HR form disclosing ownership of 23,936 shares of Westlake Corporation (US:WLK) valued at $2,796,204 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 39,607 shares of Westlake Corporation. This represents a change in shares of -39.57% during the quarter. The current value of the position is $2,067,831 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-05-13 2026-03-31 13F WESTLAKE COM 960413102 23,936 -15,671 -39.57 2,796 -4.51 0.1144
2026-02-10 2025-12-31 13F WESTLAKE COM 960413102 39,607 -17,178 -30.25 2,929 -33.07 0.0974
2025-11-12 2025-09-30 13F WESTLAKE COM 960413102 56,785 56,785 4,376 0.1191
2025-08-13 2025-06-30 13F WESTLAKE COM 960413102 0 -4,451 -100.00 0 -100.00
2025-05-13 2025-03-31 13F WESTLAKE COM 960413102 4,451 -21,944 -83.14 445 -85.29 0.0142
2025-02-11 2024-12-31 13F WESTLAKE COM 960413102 26,395 -4,347 -14.14 3,026 -34.50 0.1106
2024-11-13 2024-09-30 13F WESTLAKE COM 960413102 30,742 14,294 86.90 4,620 94.04 0.1823
2024-08-09 2024-06-30 13F WESTLAKE COM 960413102 16,448 16,448 2,382 0.1153
2024-05-06 2024-03-31 13F WESTLAKE COM 960413102 0 -9,983 -100.00 0 -100.00
2024-02-14 2023-12-31 13F WESTLAKE COM 960413102 9,983 9,983 1,397 0.0811
2023-11-07 2023-09-30 13F WESTLAKE COM 960413102 0 -17,078 -100.00 0 -100.00
2023-08-08 2023-06-30 13F WESTLAKE COM 960413102 17,078 17,078 2,040 0.1336
2022-11-07 2022-09-30 13F WESTLAKE COM 960413102 0 -5,394 -100.00 0 -100.00
2022-08-09 2022-06-30 13F WESTLAKE COM 960413102 5,394 5,394 528 0.0485
2022-05-16 2022-03-31 13F WESTLAKE CHEMICAL COM 960413102 0 -22,358 -100.00 0 -100.00
2022-02-11 2021-12-31 13F WESTLAKE CHEMICAL COM 960413102 22,358 12,353 123.47 2,171 138.31 0.1761
2021-11-09 2021-09-30 13F WESTLAKE CHEMICAL COM 960413102 10,005 7,852 364.70 911 372.02 0.0666
2021-08-12 2021-06-30 13F WESTLAKE CHEMICAL COM 960413102 2,153 2,153 193 0.0152
2020-08-13 2020-06-30 13F WESTLAKE CHEMICAL COM 960413102 0 -6,461 -100.00 0 -100.00
2020-05-13 2020-03-31 13F WESTLAKE CHEMICAL COM 960413102 6,461 6,305 4,041.67 246 2,360.00 0.1604
2020-02-10 2019-12-31 13F WESTLAKE CHEMICAL COM 960413102 156 -6,814 -97.76 10 -97.81 0.0010
2019-11-12 2019-09-30 13F WESTLAKE CHEMICAL COM 960413102 6,970 6,970 4,367.95 456 4,460.00 0.0450
2019-08-13 2019-06-30 13F WESTLAKE CHEMICAL COM 960413102 0 -5,633 -100.00 0 -100.00
2019-05-13 2019-03-31 13F WESTLAKE CHEMICAL COM 960413102 5,633 2,656 89.22 382 94.90 0.0363
2019-02-13 2018-12-31 13F WESTLAKE CHEMICAL COM 960413102 2,977 -19,560 -86.79 196 -89.54 0.0192
2018-11-13 2018-09-30 13F WESTLAKE CHEMICAL COM 960413102 22,537 22,537 657.04 1,873 855.61 0.1311
2018-08-13 2018-06-30 13F WESTLAKE CHEMICAL COM 960413102 0 -6,821 -100.00 0 -100.00
2018-05-11 2018-03-31 13F WESTLAKE CHEMICAL COM 960413102 6,821 6,821 758 0.0652
2016-08-02 2016-06-30 13F WESTLAKE CHEMICAL COM 960413102 0 -2,029 -100.00 0 -100.00
2016-04-28 2016-03-31 13F WESTLAKE CHEMICAL COM 960413102 2,029 2,029 0.00 93 0.0149
2015-10-22 2015-09-30 13F WESTLAKE CHEMICAL COM 960413102 0 -2,903 -100.00 0 -100.00
2015-07-27 2015-06-30 13F WESTLAKE CHEMICAL COM 960413102 2,903 2,903 0.00 199 0.0357
2015-01-27 2014-12-31 13F WESTLAKE CHEMICAL COM 960413102 0 -24,279 -100.00 0 -100.00
2014-10-15 2014-09-30 13F WESTLAKE CHEMICAL COM 960413102 24,279 24,279 2,102 0.2891
2014-07-08 2014-06-30 13F WESTLAKE CHEMICAL COM 960413102 0 -4,104 -100.00 0 -100.00
2014-05-21 2014-03-31 13F WESTLAKE CHEMICAL COM 960413102 4,104 2,904 242.00 271 116.80 0.0639
2013-10-28 2013-09-30 13F WESTLAKE CHEMICAL COM 960413102 1,200 1,200 125 0.0775
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.