Westlake Corporation
US ˙ NYSE ˙ US9604131022

SecurityWLK / Westlake Corporation
InstitutionMan Group plc
Latest Disclosed Ownership160,286 shares
Latest Disclosed Value $ 18,724,611
Man Group plc ownership in WLK / Westlake Corporation

On May 15, 2026 - Man Group plc filed a 13F-HR form disclosing ownership of 160,286 shares of Westlake Corporation (US:WLK) valued at $18,724,611 USD as of March 31, 2026. The entity filed a previous 13F-HR on November 14, 2025 disclosing 0 shares of Westlake Corporation. The current value of the position is $13,847,108 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 160,286 160,286 18,725 0.0209
2025-11-14 2025-09-30 13F WESTLAKE COM 960413102 0 -124,176 -100.00 0 -100.00
2025-08-14 2025-06-30 13F WESTLAKE COM 960413102 124,176 -16,715 -11.86 9,429 -33.10 0.0180
2025-05-15 2025-03-31 13F WESTLAKE COM 960413102 140,891 102,092 263.13 14,093 216.84 0.0357
2025-02-14 2024-12-31 13F WESTLAKE COM 960413102 38,799 -48,206 -55.41 4,448 -65.98 0.0117
2024-11-14 2024-09-30 13F WESTLAKE COM 960413102 87,005 7,477 9.40 13,076 13.53 0.0340
2024-08-14 2024-06-30 13F WESTLAKE COM 960413102 79,528 71,391 877.36 11,517 826.55 0.0291
2024-05-15 2024-03-31 13F WESTLAKE COM 960413102 8,137 8,137 1,243 0.0031
2023-11-14 2023-09-30 13F WESTLAKE COM 960413102 0 -9,788 -100.00 0 -100.00
2023-08-14 2023-06-30 13F WESTLAKE COM 960413102 9,788 1,169 -93.16 0.0036
2023-05-15 2023-03-31 13F WESTLAKE COM 960413102 17,102 27.62 0.0608
2023-02-14 2022-12-31 13F WESTLAKE COM 960413102 130,688 -9,380 -6.70 13,401 10.12 0.0480
2022-11-14 2022-09-30 13F WESTLAKE COM 960413102 140,068 12,169 -5.67 0.0565
2022-08-15 2022-06-30 13F WESTLAKE COM 960413102 12,900 -13.24 0.0547
2022-05-16 2022-03-31 13F WESTLAKE COM 960413102 120,495 90,243 298.30 14,869 405.92 0.0517
2022-02-14 2021-12-31 13F WESTLAKE CHEM COM 960413102 30,252 4,674 18.27 2,939 26.08 0.0094
2021-11-15 2021-09-30 13F WESTLAKE CHEM COM 960413102 25,578 -1,400 -5.19 2,331 -4.07 0.0082
2021-08-16 2021-06-30 13F WESTLAKE CHEM COM 960413102 26,978 22,521 505.30 2,430 513.64 0.0086
2021-05-17 2021-03-31 13F WESTLAKE CHEM COM 960413102 4,457 -12 -0.27 396 8.49 0.0017
2021-02-16 2020-12-31 13F WESTLAKE CHEM COM 960413102 4,469 -37,388 -89.32 365 -86.21 0.0016
2020-11-16 2020-09-30 13F WESTLAKE CHEM COM 960413102 41,857 37,488 858.05 2,646 1,030.77 0.0104
2020-08-14 2020-06-30 13F WESTLAKE CHEM COM 960413102 4,369 -15,207 -77.68 234 -68.67 0.0012
2020-05-15 2020-03-31 13F WESTLAKE CHEM COM 960413102 19,576 -18,782 -48.97 747 -72.24 0.0048
2020-02-18 2019-12-31 13F WESTLAKE CHEM COM 960413102 38,358 9,860 34.60 2,691 44.13 0.0088
2019-11-14 2019-09-30 13F WESTLAKE CHEM COM 960413102 28,498 -17,615 -38.20 1,867 -41.71 0.0069
2019-08-14 2019-06-30 13F WESTLAKE CHEM COM 960413102 46,113 37,053 408.97 3,203 419.97 0.0116
2019-05-15 2019-03-31 13F WESTLAKE CHEM COM 960413102 9,060 -35,514 -79.67 616 -79.11 0.0023
2019-02-14 2018-12-31 13F WESTLAKE CHEM COM 960413102 44,574 -1,045 -2.29 2,949 -22.21 0.0131
2018-11-14 2018-09-30 13F WESTLAKE CHEM COM 960413102 45,619 -15,293 -25.11 3,791 -42.18 0.0138
2018-08-14 2018-06-30 13F WESTLAKE CHEM COM 960413102 60,912 38,456 171.25 6,556 162.66 0.0270
2018-05-15 2018-03-31 13F WESTLAKE CHEM COM 960413102 22,456 22,456 2,496 0.0114
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.