Advanced Drainage Systems, Inc. (WMS) Ownership
WMS ownership summary
as of October 18, 2026- Institutions
- 97.0% of shares outstanding
- Insiders
- 7.17% of shares outstanding
- Shares outstanding
- 75.4M
- Float
- 69.9M shares available to trade
- Short interest
- 3.99% 3.0M shares short
- Days to cover
- 3.80 short interest up 0.2% vs prior month
- Institutions 96.97%
- Insiders 7.17%
WMS top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 9.91% | 7.5M | $957.6M | +47,211 (+0.6%) | June 30, 2026 |
| 2 | Vanguard Portfolio Management, LLC | 4.91% | 3.7M | $475.0M | +89,851 (+2.5%) | June 30, 2026 |
| 3 | Vanguard Capital Management, LLC | 4.50% | 3.4M | $435.5M | −26,666 (−0.8%) | June 30, 2026 |
| 4 | State Street Corp | 3.57% | 2.7M | $345.3M | +204,134 (+8.2%) | June 30, 2026 |
| 5 | First Trust Advisors L.P. | 3.53% | 2.7M | $341.1M | +616,696 (+30.2%) | June 30, 2026 |
| 6 | UBS Asset Mgmt Americas Inc | 3.11% | 2.3M | $300.8M | −103,500 (−4.2%) | June 30, 2026 |
| 7 | Impax Asset Management Group PLC | 2.45% | 1.8M | $236.6M | −81,568 (−4.2%) | June 30, 2026 |
| 8 | Baillie Gifford & Co Limited. | 2.43% | 1.8M | $235.3M | −212,052 (−10.4%) | June 30, 2026 |
| 9 | American Century Companies Inc | 2.17% | 1.6M | $209.5M | −23,451 (−1.4%) | June 30, 2026 |
| 10 | Morgan Stanley - Brokerage Accounts | 1.85% | 1.4M | $178.7M | +60,496 (+4.5%) | June 30, 2026 |
| 11 | Geode Capital Management, LLC | 1.81% | 1.4M | $175.3M | +22,648 (+1.7%) | June 30, 2026 |
| 12 | Amundi | 1.80% | 1.4M | $173.7M | +65,938 (+5.1%) | June 30, 2026 |
| 13 | NORGES BANK | 1.73% | 1.3M | $167.1M | +222,556 (+20.6%) | June 30, 2026 |
| 14 | Dimensional Fund Advisors, Inc. | 1.69% | 1.3M | $163.8M | +86,040 (+7.2%) | June 30, 2026 |
| 15 | Pictet Asset Manangement SA | 1.50% | 1.1M | $144.6M | −1.1M (−48.8%) | June 30, 2026 |
| 16 | Kayne Anderson Rudnick Investment Management LLC | 1.37% | 1.0M | $132.7M | −71,168 (−6.4%) | June 30, 2026 |
| 17 | Kbc Group NV | 1.23% | 924K | $118.4M | +6,715 (+0.7%) | June 30, 2026 |
| 18 | Wellington Management Company LLP | 1.11% | 840K | $107.8M | −222,743 (−20.9%) | June 30, 2026 |
| 19 | Qube Research & Technologies | 1.11% | 840K | $107.7M | +293,414 (+53.7%) | June 30, 2026 |
| 20 | Amvescap Plc. | 1.11% | 836K | $107.1M | −146,856 (−14.9%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 11 holders added 1.7M shares and 9 cut 2.0M.
WMS top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | iShares Core S&P Mid-Cap ETF | 3.31% | 2.5M | $320.2M | −888 (−0.0%) | September 30, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 3.23% | 2.4M | $312.4M | −2,782 (−0.1%) | August 31, 2026 |
| 3 | First Trust RBA Amer Indl RenaisTM ETF | 2.28% | 1.7M | $220.7M | +994 (+0.1%) | September 30, 2026 |
| 4 | Vanguard Small Cap Index | 2.25% | 1.7M | $217.5M | −65,721 (−3.7%) | September 30, 2026 |
| 5 | American Funds SMALLCAP World A | 1.29% | 972K | $124.6M | +87,685 (+9.9%) | September 30, 2026 |
| 6 | Vanguard MStar Small Cap Growth Indx Inv | 1.25% | 945K | $121.2M | −66,351 (−6.6%) | September 30, 2026 |
| 7 | Pictet-Water I EUR | 1.08% | 813K | $104.3M | −1.1M (−57.4%) | June 30, 2026 |
| 8 | American Century Ultra® Inv | 0.93% | 700K | $89.7M | −277,000 (−28.4%) | September 30, 2026 |
| 9 | BNP Paribas Aqua C C | 0.91% | 689K | $88.3M | −98 (−0.0%) | August 31, 2026 |
| 10 | BNP Paribas Aqua I | 0.91% | 688K | $88.1M | −62 (−0.0%) | August 31, 2026 |
| 11 | Global X US Infrastructure Dev ETF | 0.84% | 630K | $80.8M | +4,500 (+0.7%) | September 30, 2026 |
| 12 | iShares Global Water ETF USD Dist | 0.71% | 538K | $69.0M | — | September 30, 2026 |
| 13 | State Street® SPDR® S&P MIDCAP 400® ETF | 0.69% | 519K | $66.5M | −5,572 (−1.1%) | September 30, 2026 |
| 14 | First Trust Water ETF | 0.62% | 465K | $59.7M | — | September 30, 2026 |
| 15 | Amundi MSCI Water UCITS ETF Dist | 0.61% | 457K | $58.6M | — | September 29, 2026 |
| 16 | Eaton Vance Atlanta Capital SMID-Cap I | 0.57% | 432K | $55.4M | −9,000 (−2.0%) | August 31, 2026 |
| 17 | Vanguard Explorer Inv | 0.53% | 403K | $51.7M | −170,623 (−29.7%) | June 30, 2026 |
| 18 | Vanguard Dividend Appreciation ETF | 0.53% | 397K | $50.9M | −8,907 (−2.2%) | September 30, 2026 |
| 19 | Virtus KAR Mid-Cap Core I | 0.52% | 395K | $50.7M | −73,979 (−15.8%) | June 30, 2026 |
| 20 | State Street SPDR Port S&P 400 Md CpETF | 0.49% | 371K | $47.5M | −520 (−0.1%) | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
WMS insider transactions
latest 5| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2025-12-03 | Robert M Eversole | Sell | $152.82 | 10,569 | $1.6M |
| 2025-11-12 | D. Scott Barbour | Sell | $148.95 | 80,030 | $11.9M |
| 2025-11-12 | Thomas J Sr. Waun | Sell | $150.00 | 1,000 | $150,000 |
| 2025-11-12 | Tim A Makowski | Sell | $149.21 | 4,901 | $731,278 |
| 2025-11-11 | Thomas J Sr. Waun | Sell | $148.30 | 1,272 | $188,638 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
WMS shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns WMS
Institutional investors own 97.0% of Advanced Drainage Systems's shares and insiders 7.17%. The largest holder is BlackRock Inc with 9.91% of the shares (7.5M), as of June 30, 2026. Among the top 20 institutions, 11 added shares and 9 reduced their stake in the latest filings. Short interest is 3.99% of the float, or 3.80 days of average trading volume. The share count rose 47.8% since 2014.
Related: WMS analyst forecast, WMS key metrics, WMS dividend history. See the WMS stock overview for the latest quote and news.
WMS ownership FAQ
Who owns the most Advanced Drainage Systems stock?
The largest shareholders of Advanced Drainage Systems are BlackRock Inc (9.91%), Vanguard Portfolio Management, LLC (4.91%), Vanguard Capital Management, LLC (4.50%), State Street Corp (3.57%), First Trust Advisors L.P. (3.53%).
What percentage of Advanced Drainage Systems is owned by institutions?
Institutions hold 97.0% of Advanced Drainage Systems's shares outstanding; insiders hold 7.17%.
Which funds own Advanced Drainage Systems?
The largest fund holders of Advanced Drainage Systems are iShares Core S&P Mid-Cap ETF (3.31%), Vanguard MStar Total Stk Mkt Idx Invest (3.23%), First Trust RBA Amer Indl RenaisTM ETF (2.28%), Vanguard Small Cap Index (2.25%), American Funds SMALLCAP World A (1.29%).
What is Advanced Drainage Systems's short interest?
3.0M shares of Advanced Drainage Systems were sold short, 3.99% of the float; at the average daily volume it would take 3.80 days to cover.
Are insiders buying or selling Advanced Drainage Systems?
Of the latest 5 reported insider transactions in Advanced Drainage Systems (since November 11, 2025), 0 were purchases and 5 were sales.
How many shares of Advanced Drainage Systems are outstanding?
Advanced Drainage Systems has 75.4M shares outstanding, of which 69.9M are in the public float.