西湖公司
US ˙ NYSE ˙ US9604131022

SecurityWLK / Westlake Corporation
InstitutionStrs Ohio
Latest Disclosed Ownership799 shares
Latest Disclosed Value $ 93,339
Strs Ohio reports 0.12% decrease in ownership of WLK / Westlake Corporation

On April 24, 2026 - Strs Ohio filed a 13F-HR form disclosing ownership of 799 shares of Westlake Corporation (US:WLK) valued at $93,339 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 800 shares of Westlake Corporation. This represents a change in shares of -0.12% during the quarter. The current value of the position is $68,115 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)
2026-04-24 2026-03-31 13F WESTLAKE COM_STK 960413102 799 -1 -0.12 93 57.63 0.0004
2026-02-02 2025-12-31 13F WESTLAKE COM_STK 960413102 800 1 0.13 59 -3.28 0.0002
2025-10-30 2025-09-30 13F WESTLAKE COM_STK 960413102 799 0 0.00 62 1.67 0.0002
2025-08-04 2025-06-30 13F WESTLAKE COM_STK 960413102 799 799 61 0.0002
2025-05-28 2024-12-31 13F WESTLAKE COM_STK 960413102 0 -27,363 -100.00 0 -100.00
2024-11-01 2024-09-30 13F WESTLAKE COM_STK 960413102 27,363 328 1.21 4,112 5.03 0.0158
2024-08-05 2024-06-30 13F WESTLAKE COM_STK 960413102 27,035 410 1.54 3,915 97,775.00 0.0155
2024-05-13 2024-03-31 13F WESTLAKE COM_STK 960413102 26,625 -7,263 -21.43 4 0.00 0.0162
2024-01-30 2023-12-31 13F WESTLAKE CHEMICAL COM 960413102 33,888 -2,463 -6.78 5 0.00 0.0197
2023-10-26 2023-09-30 13F/A-1 WESTLAKE CHEMICAL COM 960413102 36,351 -14,342 -28.29 5 -33.33 0.0202
2023-10-26 2023-09-30 13F WESTLAKE CHEMICAL COM 960413102 36,351 -14,342 5 0.0202
2023-07-31 2023-06-30 13F WESTLAKE CHEMICAL COM 960413102 50,693 3,593 7.63 6 20.00 0.0256
2023-08-02 2023-03-31 13F/A-2 WESTLAKE CHEMICAL COM 960413102 47,100 -3,804 -7.47 5 0.00 0.0237
2023-08-02 2023-03-31 13F/A-1 WESTLAKE CHEMICAL COM 960413102 47,100 -3,804 5 0.0237
2023-04-27 2023-03-31 13F WESTLAKE CHEMICAL COM 960413102 47,100 -3,804 5 0.0282
2023-01-26 2022-12-31 13F WESTLAKE CHEMICAL COM 960413102 50,904 958 1.92 5 -99.88 0.0236
2022-10-27 2022-09-30 13F WESTLAKE CHEMICAL COM 960413102 49,946 19,417 63.60 4,339 45.02 0.0207
2022-07-25 2022-06-30 13F WESTLAKE CHEMICAL COM 960413102 30,529 -28,244 -48.06 2,992 -58.74 0.0135
2022-04-21 2022-03-31 13F WESTLAKE CHEMICAL COM 960413102 58,773 18,162 44.72 7,252 83.87 0.0265
2022-01-24 2021-12-31 13F WESTLAKE CHEMICAL COM 960413102 40,611 3,440 9.25 3,944 16.45 0.0137
2021-10-22 2021-09-30 13F WESTLAKE CHEMICAL COM 960413102 37,171 -6,060 -14.02 3,387 -13.02 0.0127
2021-07-26 2021-06-30 13F WESTLAKE CHEMICAL COM 960413102 43,231 1,586 3.81 3,894 5.33 0.0140
2021-04-23 2021-03-31 13F WESTLAKE CHEMICAL COM 960413102 41,645 3,064 7.94 3,697 17.44 0.0139
2021-01-25 2020-12-31 13F WESTLAKE CHEMICAL COM 960413102 38,581 137 0.36 3,148 29.55 0.0121
2020-12-14 2020-09-30 13F WESTLAKE CHEMICAL COM 960413102 38,444 17,034 79.56 2,430 111.67 0.0102
2020-07-23 2020-06-30 13F WESTLAKE CHEMICAL COM 960413102 21,410 -14,851 -40.96 1,148 -17.05 0.0050
2020-04-23 2020-03-31 13F WESTLAKE CHEMICAL COM 960413102 36,261 -45,149 -55.46 1,384 -75.76 0.0073
2020-01-24 2019-12-31 13F WESTLAKE CHEMICAL COM 960413102 81,410 0 0.00 5,710 7.07 0.0239
2019-10-21 2019-09-30 13F/A-1 WESTLAKE CHEMICAL COM 960413102 81,410 -85,000 -51.08 5,333 -53.86 0.0234
2019-10-21 2019-09-30 13F WESTLAKE CHEMICAL COM 960413102 81,410 0 5,333 23,604.1538
2019-07-25 2019-06-30 13F WESTLAKE CHEMICAL COM 960413102 166,410 -39,081 -19.02 11,558 -17.11 0.0514
2019-04-19 2019-03-31 13F WESTLAKE CHEMICAL COM 960413102 205,491 25,491 14.16 13,944 17.08 0.0632
2019-01-23 2018-12-31 13F WESTLAKE CHEMICAL COM 960413102 180,000 -118,796 -39.76 11,910 -52.04 0.0605
2018-10-19 2018-09-30 13F WESTLAKE CHEMICAL COM 960413102 298,796 -16,146 -5.13 24,832 -26.74 0.1089
2018-08-06 2018-06-30 13F WESTLAKE CHEMICAL COM 960413102 314,942 -58 -0.02 33,897 -3.18 0.1459
2018-04-20 2018-03-31 13F WESTLAKE CHEMICAL COM 960413102 315,000 62,754 24.88 35,012 30.30 0.1548
2018-01-23 2017-12-31 13F WESTLAKE CHEMICAL COM 960413102 252,246 30,000 13.50 26,871 45.52 0.1148
2017-10-23 2017-09-30 13F WESTLAKE CHEMICAL COM 960413102 222,246 0 0.00 18,466 25.50 0.0793
2017-07-26 2017-06-30 13F WESTLAKE CHEMICAL COM 960413102 222,246 -24,754 -10.02 14,714 -9.81 0.0656
2017-04-26 2017-03-31 13F WESTLAKE CHEMICAL COM 960413102 247,000 246,006 24,749.09 16,314 35,365.22 0.0707
2016-04-25 2016-03-31 13F/A-1 WESTLAKE CHEMICAL COM 960413102 994 -119,837 -99.18 46 -99.30 0.0002
2016-01-28 2015-12-31 13F WESTLAKE CHEMICAL COM 960413102 120,831 -432 -0.36 6,563 4.31 0.0293
2015-10-21 2015-09-30 13F WESTLAKE CHEMICAL COM 960413102 121,263 -349,659 -74.25 6,292 -80.52 0.0299
2015-08-04 2015-06-30 13F WESTLAKE CHEMICAL COM 960413102 470,922 200,000 73.82 32,300 65.73 0.1418
2015-04-27 2015-03-31 13F/A-1 WESTLAKE CHEMICAL COM 960413102 270,922 -99,078 -26.78 19,490 -13.77 0.0860
2015-04-21 2015-03-31 13F WESTLAKE CHEMICAL COM 960413102 19,490,129 19,423
2015-01-23 2014-12-31 13F WESTLAKE CHEMICAL COM 960413102 370,000 0 0.00 22,603 -29.45 0.0980
2014-10-29 2014-09-30 13F/A-1 WESTLAKE CHEMICAL COM 960413102 370,000 -25,000 -6.33 32,038 -3.16 0.1415
2014-10-20 2014-09-30 13F WESTLAKE CHEMICAL COM 960413102 370,000 32,038
2014-07-24 2014-06-30 13F WESTLAKE CHEMICAL COM 960413102 395,000 -125,000 -24.04 33,085 -3.86 0.1474
2014-04-28 2014-03-31 13F WESTLAKE CHEMICAL COM 960413102 520,000 260,000 100.00 34,414 8.43 0.1548
2014-01-30 2013-12-31 13F WESTLAKE CHEMICAL COM 960413102 260,000 15,000 6.12 31,738 23.77 0.1427
2013-10-24 2013-09-30 13F WESTLAKE CHEMICAL COM 960413102 245,000 0 0.00 25,642 8.56 0.1130
2013-08-12 2013-06-30 13F WESTLAKE CHEMICAL COM 960413102 245,000 245,000 23,620 0.1015
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.