Advanced Drainage Systems, Inc. (WMS) Shareholders & Insider Trades
Advanced Drainage Systems shareholders at a glance
The largest holder of Advanced Drainage Systems stock is BlackRock Advisors LLC, with 6.6 million shares (8.79% of the company), worth about $900.00 million as of September 25, 2026. The 10 largest holders together own 41.6%.
In Q2 2026, 575 institutional holdings reports listed shares worth $11.30 billion.
Insiders reported 45 transactions in the last two years: 7 sales worth $15.67 million and no purchases. The newest one on file is from March 13, 2026 (Barbour D Scott, Chief Executive Officer).
Major holders as of September 25, 2026; quarterly totals from institutional holdings reports (latest Q2 2026); insider transactions on file through March 13, 2026.
Advanced Drainage Systems, Inc.
Shareholders Summary
2026Q2
Ownership by Type
Geographic Distribution
Largest Advanced Drainage Systems shareholders
| Holder | Shares | % of company | Value |
|---|---|---|---|
| BlackRock Advisors LLC | 6.6 million | 8.79% | $900.0M |
| Advanced Drainage Systems, Inc. (ESOP) | 4.6 million | 6.14% | $628.0M |
| Vanguard Portfolio Management LLC | 3.7 million | 4.91% | $503.0M |
| Vanguard Capital Management LLC | 3.4 million | 4.50% | $461.0M |
| State Street Corporation | 2.7 million | 3.57% | $366.0M |
| First Trust Advisors LP | 2.7 million | 3.53% | $361.0M |
| UBS Asset Management (UK) Ltd. | 2.3 million | 3.11% | $319.0M |
| Impax Asset Management Ltd. | 1.8 million | 2.45% | $251.0M |
| Baillie Gifford & Co. | 1.8 million | 2.43% | $249.0M |
| American Century Cos., Inc. | 1.6 million | 2.17% | $222.0M |
As of September 25, 2026.
Advanced Drainage Systems institutional holdings by quarter
| Quarter | Reports | Shares | Value |
|---|---|---|---|
| Q2 2026 | 575 | – | $11.3B |
| Q1 2026 | 600 | 69.6 million | $9.5B |
| Q4 2025 | 568 | 71.7 million | $10.4B |
| Q3 2025 | 521 | 73.1 million | $10.1B |
| Q2 2025 | 507 | 73.0 million | $8.4B |
| Q1 2025 | 495 | 70.1 million | $7.6B |
| Q4 2024 | 492 | 67.6 million | $7.8B |
| Q3 2024 | 516 | 66.5 million | $10.4B |
Shares and value held by institutions that file quarterly holdings reports (options not included).
Advanced Drainage Systems insider trades
| Insider | Date | Title | Transaction | Value |
|---|---|---|---|---|
| Barbour D Scott | Mar 13, 2026 | Chief Executive Officer | Stock Gift at price 0.00 per share. | – |
| Barbour D Scott | Mar 4, 2026 | Chief Executive Officer | Stock Gift at price 0.00 per share. | – |
| Eversole Robert M. | Dec 5, 2025 | Director | Stock Gift at price 0.00 per share. | – |
| Eversole Robert M. | Dec 3, 2025 | Director | Sale at price 152.82 per share. | $1.6M |
| Coleman Michael B. | Dec 2, 2025 | Director | Stock Gift at price 0.00 per share. | – |
| Waun Thomas J Sr | Nov 26, 2025 | Officer | Sale at price 155.00 per share. | $232,500 |
| Barbour D Scott | Nov 25, 2025 | Chief Executive Officer | Stock Gift at price 0.00 per share. | – |
| Barbour D Scott | Nov 12, 2025 | Chief Executive Officer | Conversion of Exercise of derivative security at price 25.75 per share. | $2.1M |
| Makowski Tim A | Nov 12, 2025 | Officer | Sale at price 149.19 - 149.21 per share. | $731,276 |
| Barbour D Scott | Nov 12, 2025 | Chief Executive Officer | Sale at price 148.01 - 150.66 per share. | $11.9M |
| Waun Thomas J Sr | Nov 12, 2025 | Officer | Sale at price 148.30 - 150.00 per share. | $338,690 |
| Eversole Robert M. | Nov 10, 2025 | Director | Stock Gift at price 0.00 per share. | – |
Newest 12 of 45 insider transactions in the last two years.
Questions and answers
Who owns the most Advanced Drainage Systems stock?
BlackRock Advisors LLC, with 8.79% of the company (as of September 25, 2026). Next: Advanced Drainage Systems, Inc. (ESOP) (6.14%) and Vanguard Portfolio Management LLC (4.91%).
How many institutions own Advanced Drainage Systems stock?
575 institutional holdings reports listed Advanced Drainage Systems shares in Q2 2026 worth $11.30 billion.
Are Advanced Drainage Systems insiders buying or selling the stock?
In the last two years insiders reported 7 sales and no purchases (45 transactions in all); the newest on file is from March 13, 2026.
