Who owns Advanced Drainage Systems (WMS)
Which tracked institutional funds hold WMS, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See WMS company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
192 tracked funds added or opened WMS while 116 trimmed or exited it between 2026-Q1 and 2026-Q2 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
WMS’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes WMS more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in WMS divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 517 tracked filers holding WMS, 246 increased or opened the position and 319 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in WMS between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 18
- Jupiter Topco LLC$57M
- SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC$19M
- HITE Hedge Asset Management LLC$9M
- Lighthouse Investment Partners, LLC$4M
- ABN AMRO INVESTMENT SOLUTIONS$2M
- Aventail Capital Group, LP$2M
Full exits 70
- Amundi$177M
- KBC Group NV$126M
- WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC$90M
- JANUS HENDERSON GROUP PLC$81M
- Alyeska Investment Group, L.P.$35M
- Mediolanum International Funds Ltd$28M
Largest adds
- BlackRock, Inc.$346M
- FIRST TRUST ADVISORS LP$137M
- NORGES BANK$133M
- VANGUARD PORTFOLIO MANAGEMENT LLC$86M
- STATE STREET CORP$81M
- BAMCO INC /NY/$67M
Largest trims
- Pictet Asset Management Holding SA$125M
- ADAGE CAPITAL PARTNERS GP, L.L.C.$52M
- WESTWOOD HOLDINGS GROUP INC$18M
- WELLINGTON MANAGEMENT GROUP LLP$13M
- JANE STREET GROUP, LLC$13M
- Gotham Asset Management, LLC$12M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 7,469,940 | $1.2B | 12.3% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 3,705,538 | $582M | 6.1% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC trimmed | 3,397,037 | $533M | 5.6% | 2026-Q2 |
| STATE STREET CORP added | 2,693,665 | $423M | 4.4% | 2026-Q2 |
| FIRST TRUST ADVISORS LP added | 2,660,753 | $418M | 4.4% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 2,346,623 | $368M | 3.8% | 2026-Q2 |
| Impax Asset Management Group plc trimmed | 1,845,942 | $290M | 3.0% | 2026-Q2 |
| BAILLIE GIFFORD & CO trimmed | 1,835,297 | $288M | 3.0% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC trimmed | 1,634,302 | $257M | 2.7% | 2026-Q2 |
| MORGAN STANLEY added | 1,393,836 | $219M | 2.3% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,367,443 | $215M | 2.2% | 2026-Q2 |
| NORGES BANK added | 1,303,735 | $205M | 2.1% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 1,277,818 | $201M | 2.1% | 2026-Q2 |
| Pictet Asset Management Holding SA trimmed | 1,127,974 | $177M | 1.8% | 2026-Q2 |
| KAYNE ANDERSON RUDNICK INVESTMENT MANAGEMENT LLC trimmed | 1,035,255 | $162M | 1.7% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 840,488 | $132M | 1.4% | 2026-Q2 |
| Qube Research & Technologies Ltd added | 839,820 | $132M | 1.4% | 2026-Q2 |
| Invesco Ltd. trimmed | 835,672 | $131M | 1.4% | 2026-Q2 |
| Impactive Capital LP trimmed | 782,790 | $123M | 1.3% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 696,500 | $109M | 1.1% | 2026-Q2 |
| BAMCO INC /NY/ added | 680,431 | $107M | 1.1% | 2026-Q2 |
| Capital International Investors added | 657,285 | $103M | 1.1% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 641,404 | $101M | 1.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 634,269 | $100M | 1.0% | 2026-Q2 |
| Mirova US LLC trimmed | 619,117 | $97M | 1.0% | 2026-Q2 |
| NORTHERN TRUST CORP added | 594,404 | $93M | 1.0% | 2026-Q2 |
| Liontrust Investment Partners LLP trimmed | 558,705 | $88M | 0.9% | 2026-Q2 |
| SCHRODER INVESTMENT MANAGEMENT GROUP added | 551,815 | $85M | 0.9% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 528,473 | $83M | 0.9% | 2026-Q2 |
| Triodos Investment Management BV trimmed | 528,311 | $83M | 0.9% | 2026-Q2 |
| Hill City Capital, LP added | 480,000 | $75M | 0.8% | 2026-Q2 |
| Bank of New York Mellon Corp trimmed | 472,119 | $74M | 0.8% | 2026-Q2 |
| Schonfeld Strategic Advisors LLC trimmed | 460,060 | $72M | 0.8% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 457,355 | $72M | 0.8% | 2026-Q2 |
| Interval Partners, LP added | 452,250 | $71M | 0.7% | 2026-Q2 |
| Swedbank AB added | 410,660 | $64M | 0.7% | 2026-Q2 |
| BROWN BROTHERS HARRIMAN & CO trimmed | 405,502 | $64M | 0.7% | 2026-Q2 |
| ACK Asset Management LLC | 390,000 | $61M | 0.6% | 2026-Q2 |
| Allianz Asset Management GmbH added | 381,545 | $52M | 0.5% | 2026-Q2 |
| WESTWOOD HOLDINGS GROUP INC trimmed | 367,876 | $58M | 0.6% | 2026-Q2 |
| Jupiter Topco LLC new | 361,701 | $57M | 0.6% | 2026-Q2 |
| Corient Private Wealth LP added | 349,803 | $55M | 0.6% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. added | 342,925 | $54M | 0.6% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 340,259 | $53M | 0.6% | 2026-Q2 |
| STIFEL FINANCIAL CORP trimmed | 316,418 | $50M | 0.5% | 2026-Q2 |
| MARSHALL WACE, LLP added | 314,509 | $49M | 0.5% | 2026-Q2 |
| FRANKLIN RESOURCES INC added | 301,831 | $47M | 0.5% | 2026-Q2 |
| PNC Financial Services Group, Inc. added | 277,646 | $44M | 0.5% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 276,016 | $43M | 0.5% | 2026-Q2 |
| Robeco Schweiz AG trimmed | 271,735 | $43M | 0.4% | 2026-Q2 |
| UBS Group AG added | 270,881 | $43M | 0.4% | 2026-Q2 |
| Capital World Investors added | 270,582 | $42M | 0.4% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 266,824 | $41M | 0.4% | 2026-Q2 |
| TD Asset Management Inc trimmed | 257,884 | $40M | 0.4% | 2026-Q2 |
| GENEVA CAPITAL MANAGEMENT LLC trimmed | 245,893 | $39M | 0.4% | 2026-Q2 |
| Legal & General Group Plc added | 243,190 | $38M | 0.4% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 225,799 | $35M | 0.4% | 2026-Q2 |
| FIL Ltd added | 221,192 | $35M | 0.4% | 2026-Q2 |
| Grantham, Mayo, Van Otterloo & Co. LLC added | 218,069 | $34M | 0.4% | 2026-Q2 |
| Owls Nest Partners IA, LLC trimmed | 211,839 | $33M | 0.3% | 2026-Q2 |
| Russell Investments Group, Ltd. trimmed | 201,716 | $32M | 0.3% | 2026-Q2 |
| Aberdeen Group plc trimmed | 201,310 | $32M | 0.3% | 2026-Q2 |
| Quantinno Capital Management LP trimmed | 197,347 | $31M | 0.3% | 2026-Q2 |
| VAN LANSCHOT KEMPEN INVESTMENT MANAGEMENT N.V. trimmed | 197,030 | $31M | 0.3% | 2026-Q2 |
| STOREBRAND ASSET MANAGEMENT AS added | 189,377 | $30M | 0.3% | 2026-Q2 |
| Gotham Asset Management, LLC trimmed | 182,934 | $29M | 0.3% | 2026-Q2 |
| RHUMBLINE ADVISERS trimmed | 182,486 | $29M | 0.3% | 2026-Q2 |
| J. Safra Sarasin Holding AG added | 181,952 | $28M | 0.3% | 2026-Q2 |
| MACKENZIE FINANCIAL CORP trimmed | 175,879 | $28M | 0.3% | 2026-Q2 |
| MIROVA added | 173,559 | $27M | 0.3% | 2026-Q2 |
| LOOMIS SAYLES & CO L P trimmed | 169,143 | $27M | 0.3% | 2026-Q2 |
| Clearbridge Investments, LLC added | 166,390 | $26M | 0.3% | 2026-Q2 |
| SCOPUS ASSET MANAGEMENT, L.P. added | 166,227 | $26M | 0.3% | 2026-Q2 |
| WCM INVESTMENT MANAGEMENT, LLC added | 165,114 | $26M | 0.3% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC added | 162,716 | $26M | 0.3% | 2026-Q2 |
| Epoch Investment Partners, Inc. trimmed | 152,667 | $24M | 0.3% | 2026-Q2 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. trimmed | 150,000 | $24M | 0.2% | 2026-Q2 |
| Zurcher Kantonalbank (Zurich Cantonalbank) added | 149,275 | $23M | 0.2% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 147,129 | $23M | 0.2% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 147,054 | $23M | 0.2% | 2026-Q2 |
| JUPITER ASSET MANAGEMENT LTD | 146,197 | $23M | 0.2% | 2026-Q2 |
| CRAMER ROSENTHAL MCGLYNN LLC added | 143,426 | $23M | 0.2% | 2026-Q2 |
| Mitsubishi UFJ Trust & Banking Corp trimmed | 142,271 | $22M | 0.2% | 2026-Q2 |
| Swiss National Bank trimmed | 140,700 | $22M | 0.2% | 2026-Q2 |
| ROYAL BANK OF CANADA trimmed | 138,901 | $22M | 0.2% | 2026-Q2 |
| California Public Employees Retirement System trimmed | 138,509 | $22M | 0.2% | 2026-Q2 |
| NOMURA ASSET MANAGEMENT CO LTD added | 133,536 | $21M | 0.2% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 133,227 | $21M | 0.2% | 2026-Q2 |
| Rathbones Group PLC added | 131,747 | $21M | 0.2% | 2026-Q2 |
| Baird Financial Group, Inc. added | 128,123 | $20M | 0.2% | 2026-Q2 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ trimmed | 125,282 | $20M | 0.2% | 2026-Q2 |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main added | 124,095 | $19M | 0.2% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 120,446 | $19M | 0.2% | 2026-Q2 |
| SILVERCREST ASSET MANAGEMENT GROUP LLC added | 119,246 | $19M | 0.2% | 2026-Q2 |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC new | 118,313 | $19M | 0.2% | 2026-Q2 |
| EXCHANGE TRADED CONCEPTS, LLC added | 116,548 | $18M | 0.2% | 2026-Q2 |
| ABN AMRO Bank N.V. trimmed | 114,578 | $18M | 0.2% | 2026-Q2 |
| Nuveen, LLC trimmed | 111,795 | $18M | 0.2% | 2026-Q2 |
| Perpetual Ltd added | 106,416 | $17M | 0.2% | 2026-Q2 |
| BDF-GESTION trimmed | 11,686 | $30M | 0.3% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.