Advanced Drainage Systems, Inc.
Advanced Drainage Systems, Inc. (WMS) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · WMS · as of Sep 30, 2025
Ownership Breakdown
512
Institutional Holders
▲ 18 vs Q2
$10.10B
Total Inst. Value
▲ $1.76B vs Q2
76.60M
Shares Outstanding
freeFloat 93.02%
72.85M
13F Shares Held
▲ 174,905 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
WMS largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC plastics foam products | 7.48M | 9.65% | 9.65% | $1.04T | Nov 7, 2025 | ▼ 28.2K |
BLACKROCK, INC. plastics foam products | 7.04M | 9.08% | 9.08% | $976.85B | Nov 12, 2025 | ▼ 28.2K |
UBS ASSET MANAGEMENT AMERICAS INC plastics foam products | 2.81M | 3.63% | 3.63% | $390.00B | Nov 14, 2025 | ▼ 300.8K |
STATE STREET CORP plastics foam products | 2.55M | 3.29% | 3.29% | $353.95B | Nov 14, 2025 | ▲ 75.8K |
IMPAX ASSET MANAGEMENT GROUP PLC plastics foam products | 2.50M | 3.22% | 3.22% | $345.79B | Nov 6, 2025 | ▼ 543.8K |
FIRST TRUST ADVISORS LP plastics foam products | 2.42M | 3.12% | 3.12% | $335.23B | Nov 12, 2025 | ▲ 238.2K |
BAILLIE GIFFORD & CO plastics foam products | 2.40M | 3.09% | 3.09% | $332.20B | Oct 31, 2025 | ▼ 77.4K |
PICTET ASSET MANAGEMENT HOLDING SA plastics foam products | 2.07M | 2.67% | 2.67% | $287.30B | Nov 18, 2025 | ▼ 532.4K |
MORGAN STANLEY plastics foam products | 2.00M | 2.58% | 2.58% | $277.54B | May 27, 2026 | ▲ 326.7K |
IMPACTIVE CAPITAL LP plastics foam products | 1.66M | 2.15% | 2.15% | $230.80B | Nov 14, 2025 | — held |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
23
Increased
+3.76M shares1
New Positions
first time holders24
Decreased
−2.75M shares0
Sold Out
fully exitedNet shares change (top 50)
+1.01M
+3.76M / −2.75M
Net new holders
+0
1 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
WMS insider trading · insider activity
Source: SEC Form 4
24
Buy transactions
25
Sell transactions
0.96
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
TAYLOR CRAIG J. Executive Vice President | May 26, 2026 | Award | 1,530 | — | — | 14.9K | Form 4 ↗ |
TAYLOR CRAIG J. Executive Vice President | May 26, 2026 | Award | 3,406 | $138.09 | $470.3K | 3.4K | Form 4 ↗ |
Martz Bret See Remarks | May 26, 2026 | Award | 1,252 | — | — | 3.1K | Form 4 ↗ |
Martz Bret See Remarks | May 26, 2026 | Award | 2,787 | $138.09 | $384.9K | 2.8K | Form 4 ↗ |
TALLEY KEVIN C EVP and CAO | May 26, 2026 | Award | 1,217 | — | — | 63.5K | Form 4 ↗ |
TALLEY KEVIN C EVP and CAO | May 26, 2026 | Award | 2,709 | $138.09 | $374.1K | 2.7K | Form 4 ↗ |
Cottrill Scott A EVP, CFO AND SECRETARY | May 26, 2026 | Award | 2,503 | — | — | 110.5K | Form 4 ↗ |
Cottrill Scott A EVP, CFO AND SECRETARY | May 26, 2026 | Award | 5,573 | $138.09 | $769.6K | 5.6K | Form 4 ↗ |
BARBOUR D. SCOTT See Remarks | May 26, 2026 | Award | 9,036 | — | — | 77.3K | Form 4 ↗ |
BARBOUR D. SCOTT See Remarks | May 26, 2026 | Award | 20,124 | $138.09 | $2.78M | 20.1K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Advanced Drainage Systems, Inc. (WMS) is primarily owned by institutional investors, who hold approximately 95.1% of total shares outstanding. Company insiders own approximately 6.98%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Advanced Drainage Systems, Inc. is VANGUARD GROUP INC, holding approximately 7.48 million shares — equal to 9.65% of outstanding shares — as of September 30, 2025.
A total of 512 institutional investors currently hold WMS stock, with a combined institutional value of approximately $10.10 billion as of the most recent 13F filing period.
Frequently asked questions
WMS ownershipAdvanced Drainage Systems, Inc. (WMS) is primarily owned by institutional investors, who hold approximately 95.1% of shares. The largest shareholder is VANGUARD GROUP INC with a 9.65% stake. Company insiders hold 6.98%. Data sourced from SEC Form 13F as of September 30, 2025.