Advanced Drainage Systems Inc
Ownership
Ownership Structure
Who owns Advanced Drainage Systems Inc (WMS)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 92.7% of the shares are freely tradable; institutional investors hold 96.9%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 9.84 | 7,422,729 | +4.4 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 4.80 | 3,615,687 | +0.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 4.54 | 3,423,703 | +0.0 | 03/31/2026 |
| First Trust Advisors L.P. | 3.53 | 2,660,753 | +30.2 | 06/30/2026 |
| State Street Corp | 3.30 | 2,489,531 | +0.8 | 03/31/2026 |
| UBS Asset Mgmt Americas Inc | 3.25 | 2,450,123 | -4.1 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| UBS: Global Equity | 6.06 | 4,572,430 | +0.0 | 03/31/2026 |
| iShares Core S&P Mid-Cap ETF | 3.33 | 2,510,082 | +0.0 | 08/31/2026 |
| Vanguard MStar Total Stk Mkt Idx Invest | 3.24 | 2,439,458 | +0.3 | 07/31/2026 |
| Pictet-Water I EUR | 2.53 | 1,908,359 | +11.1 | 05/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Eversole Robert M | Director | 56,101 | 7,051,896 $ | Jul 16, 2026 | both |
| Barbour D. Scott | See Remarks | 51,652 | 6,492,656 $ | Aug 20, 2026 | indirect |
| Fratto Tanya D | Director | 30,552 | 3,840,386 $ | Jul 16, 2026 | direct |
| Perez De La Mesa Manuel J | Director | 25,070 | 3,151,299 $ | Jul 16, 2026 | direct |
| Fischer Alexander R | Director | 17,564 | 2,207,795 $ | Jul 16, 2026 | direct |
| Seetharam Anil | Director | 16,240 | 2,041,368 $ | Jul 16, 2026 | direct |
| Coleman Michael B. | Director | 12,587 | 1,582,186 $ | Jul 16, 2026 | direct |
| Coyle Patrick M. Jr | See Remarks | 10,039 | 1,261,902 $ | Sep 1, 2026 | direct |
| Gast Kelly S. | Director | 8,981 | 1,128,912 $ | Jul 16, 2026 | direct |
| Chaibi Anesa | Director | 8,698 | 1,093,339 $ | Jul 16, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Sep 1, 2026 | Coyle Patrick M. Jr | See Remarks | Other | 26 | 130.75 | 3,400 |
| Sep 1, 2026 | Eversole Robert M | Director | Other | 2,386 | 0.00 | – |
| Aug 20, 2026 | Barbour D. Scott | See Remarks | Other | 2,000 | 0.00 | – |
| Jul 16, 2026 | Fratto Tanya D | Director | Other | 1,110 | 0.00 | – |
| Jul 16, 2026 | Gast Kelly S. | Director | Other | 1,110 | 0.00 | – |
| Jul 16, 2026 | Coleman Michael B. | Director | Other | 1,110 | 0.00 | – |
| Jul 16, 2026 | Seetharam Anil | Director | Other | 1,782 | 0.00 | – |
| Jul 16, 2026 | Chaibi Anesa | Director | Other | 1,110 | 0.00 | – |
| Jul 16, 2026 | Perez De La Mesa Manuel J | Director | Other | 1,782 | 0.00 | – |
| Jul 16, 2026 | Eversole Robert M | Director | Other | 2,253 | 0.00 | – |
| Jul 16, 2026 | Fischer Alexander R | Director | Other | 1,110 | 0.00 | – |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.