Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in WLK held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | Orbis Allan Gray Ltd | 5.3M | $618.4M | +20.7% | 4.133% | 2.61% |
| 2 | Capital World Investors | 4.2M | $491.9M | +93.9% | 3.288% | 0.07% |
| 3 | BlackRock, Inc. | 3.1M | $359.7M | -5.6% | 2.404% | 0.01% |
| 4 | BRANDES INVESTMENT PARTNERS, LP | 1.8M | $215.3M | +10.3% | 1.439% | 1.52% |
| 5 | WELLINGTON MANAGEMENT GROUP LLP | 1.8M | $209.5M | -57.5% | 1.400% | 0.04% |
| 6 | VANGUARD PORTFOLIO MANAGEMENT LLC | 1.8M | $206.7M | β | 1.382% | 0.01% |
| 7 | DIMENSIONAL FUND ADVISORS LP | 1.5M | $171.3M | -22.3% | 1.145% | 0.04% |
| 8 | VANGUARD CAPITAL MANAGEMENT LLC | 1.5M | $170.0M | β | 1.136% | 0.00% |
| 9 | GOLDMAN SACHS GROUP INC | 1.4M | $162.8M | +84.8% | 1.088% | 0.02% |
| 10 | STATE STREET CORP | 1.4M | $161.3M | -1.2% | 1.078% | 0.01% |
| 11 | FMR LLC | 1.3M | $153.3M | +473.5% | 1.025% | 0.01% |
| 12 | UBS ASSET MANAGEMENT AMERICAS INC | 981K | $114.6M | +6.1% | 0.766% | 0.02% |
| 13 | MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | 944K | $110.3M | +7.6% | 0.737% | 0.15% |
| 14 | CITADEL ADVISORS LLC | 847K | $99.0M | +131.0% | 0.661% | 0.05% |
| 15 | UBS Group AG | 811K | $94.8M | +25.2% | 0.633% | 0.01% |
| 16 | Holocene Advisors, LP | 730K | $85.3M | -40.2% | 0.570% | 0.21% |
| 17 | GEODE CAPITAL MANAGEMENT, LLC | 614K | $71.8M | +3.3% | 0.480% | 0.00% |
| 18 | Nuveen, LLC | 565K | $66.0M | -13.5% | 0.441% | 0.02% |
| 19 | MORGAN STANLEY | 487K | $56.8M | -35.9% | 0.380% | 0.00% |
| 20 | Erste Asset Management GmbH | 395K | $45.8M | -5.9% | 0.308% | 0.42% |
| 21 | SCHRODER INVESTMENT MANAGEMENT GROUP | 375K | $43.4M | β | 0.292% | 0.04% |
| 22 | BALYASNY ASSET MANAGEMENT LLC | 370K | $43.2M | β | 0.289% | 0.15% |
| 23 | JACOBS LEVY EQUITY MANAGEMENT, INC | 349K | $40.8M | -47.8% | 0.273% | 0.17% |
| 24 | Woodline Partners LP | 337K | $39.4M | -46.3% | 0.263% | 0.15% |
| 25 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 312K | $36.4M | +4.9% | 0.243% | 0.01% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in WLK β a direct measure of their conviction.
Filings activity in WLK during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 327 | +11% | 42.49% | +14.05 pp | $4.82B | +49% |
| Q4 2025 | 295 | +1.0% | 28.44% | +1.74 pp | $3.22B | +6.5% |
| Q3 2025 | 292 | 2.0% | 26.70% | +2.08 pp | $3.03B | +8.5% |
| Q2 2025 | 298 | 15% | 24.62% | 5.24 pp | $2.79B | 18% |
| Q1 2025 | 352 | 5.4% | 29.86% | 3.98 pp | $3.39B | 12% |
| Q4 2024 | 372 | 4.1% | 33.84% | 8.55 pp | $3.84B | 20% |
| Q3 2024 | 388 | +4.0% | 42.39% | +0.39 pp | $4.80B | +0.9% |
| Q2 2024 | 373 | β | 42.00% | β | $4.76B | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying WLK stock.
Based on Q1 2026 13F filings, institutional ownership of Westlake Corporation stands at 42.5%, held across 327 reporting institutions.
Orbis Allan Gray Ltd is the largest reported institutional holder of WLK, with approximately 5,293,519 shares worth $0.62B as of Q1 2026.
Yes β 1 widely-followed marquee investor appear among the top 25 institutional holders of WLK, including CITADEL ADVISORS LLC.
Our composite Smart Money Score for WLK is 66 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
90 institutions opened new positions in WLK during Q1 2026, while 58 fully exited. 200 added to existing positions and 34 trimmed.
WLK institutional ownership rose by 14.05 percentage points quarter-over-quarter, with a net change of +32 holders.
The top 10 institutions account for 57.4% of all reported 13F value in WLK, and the top 25 account for 80.3%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Westlake Corporation (WLK) Institutional Ownership