551 institutional investment managers reported WMS positions in their Form 13F filings for Q2 2026, holding 69,653,381 shares worth $10.9B in total. BlackRock, Inc. reported the largest position.

Are funds buying or selling WMS?

In Q2 2026, 51 managers opened new WMS positions, 195 added, 205 trimmed and 78 sold out. Managers that filed in both quarters added a net 515,789 shares.

How current is this WMS institutional ownership data?

It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.

Funds · WMS

Who owns WMS?

Institutional ownership of Advanced Drainage Systems Inc. from Form 13F, Q2 2026

551 institutional managers reported holding Advanced Drainage Systems Inc. (WMS) in Form 13F filings for Q2 2026, with 69,653,381 shares worth $10.9B. The largest reported holder was BlackRock, Inc. Managers that filed both quarters added a net 515,789 shares (+0.8%). 51 opened new positions and 78 sold out.

Funds holding: 551
Value held: $10.9B
New / sold out: 51 / 78
Net shares, same filers: +0.8%

Holdings as of June 30, 2026, the end of Q2 2026. Managers have 45 days after a quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.

Largest holders of WMS

Fund	Value	Share of 13F holdings	Shares	Move
BlackRock, Inc.	$1.2B	10.7%	7,469,940	Added
Vanguard Portfolio Management LLC	$582M	5.3%	3,705,538	Added
Vanguard Capital Management LLC	$533M	4.9%	3,397,037	Trimmed
State Street Corp	$423M	3.9%	2,693,665	Added
First Trust Advisors LP	$418M	3.8%	2,660,753	Added
UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC	$368M	3.4%	2,346,623	Trimmed
Impax Asset Management Group plc	$290M	2.7%	1,845,942	Trimmed
Baillie Gifford & Co	$288M	2.6%	1,835,297	Trimmed
American Century Companies Inc	$257M	2.3%	1,634,302	Trimmed
Morgan Stanley	$219M	2.0%	1,393,836	Added
Geode Capital Management, LLC	$215M	2.0%	1,367,443	Added
Amundi	$213M	1.9%	1,354,610	Added
Norges Bank	$205M	1.9%	1,303,735	New
Dimensional Fund Advisors LP	$201M	1.8%	1,277,818	Added
Pictet Asset Management Holding SA	$177M	1.6%	1,127,974	Trimmed
Kayne Anderson Rudnick Investment Management LLC	$162M	1.5%	1,035,255	Trimmed
KBC Group NV	$145M	1.3%	923,696	Added
Wellington Management Group LLP	$132M	1.2%	840,488	Trimmed
Qube Research & Technologies Ltd	$132M	1.2%	839,820	Added
Invesco Ltd.	$131M	1.2%	835,672	Trimmed
Impactive Capital LP	$123M	1.1%	782,790	Trimmed
Charles Schwab Investment Management Inc	$109M	1.0%	696,500	Trimmed
Bamco Inc	$107M	1.0%	680,431	Added
Capital International Investors	$103M	0.9%	657,285	Added
Goldman Sachs Group Inc	$101M	0.9%	641,404	Added

Share of 13F holdings is each fund's shares as a share of the 69,653,381 WMS shares all 13F filers reported, not of shares outstanding.

Biggest buyers in Q2 2026

Norges Bank New+$205M
First Trust Advisors LP Added+$96.8M
Bamco Inc Added+$61.1M
Balyasny Asset Management L.P. Added+$53.3M
Marshall Wace, LLP Added+$48.3M
Qube Research & Technologies Ltd Added+$46.1M
Swedbank AB Added+$38.6M
Thrivent Financial for Lutherans Added+$34.8M
State Street Corp Added+$32.0M
Goldman Sachs Group Inc Added+$29.8M

Biggest sellers in Q2 2026

Pictet Asset Management Holding SA Trimmed-$169M
William Blair Investment Management, LLC Sold out-$89.9M
Adage Capital Partners GP, L.l.c. Trimmed-$62.8M
Alyeska Investment Group, L.P. Sold out-$35.4M
Wellington Management Group LLP Trimmed-$35.0M
Baillie Gifford & Co Trimmed-$33.3M
Westwood Holdings Group Inc Trimmed-$29.1M
Mediolanum International Funds Ltd Sold out-$28.0M
Invesco Ltd. Trimmed-$23.1M
Gotham Asset Management, LLC Trimmed-$17.5M

The change in shares since the quarter before, adjusted for stock splits and priced at the Q2 2026 value per share. Funds bought $1.1B and sold $1.0B; 195 added and 205 trimmed.

Schedule 13D and 13G filings on WMS

Owners of more than 5% must file within days, so these can be newer than the 13F data.

2026-02-13DELAWARE CHARTER GUARANTEE & TRUST CO SCHEDULE 13G filed by Advanced Drainage Systems Inc.Schedule 13G

Questions about WMS ownership

Who owns WMS stock?: 551 institutional investment managers reported WMS positions in their Form 13F filings for Q2 2026, holding 69,653,381 shares worth $10.9B in total. BlackRock, Inc. reported the largest position.
Are funds buying or selling WMS?: In Q2 2026, 51 managers opened new WMS positions, 195 added, 205 trimmed and 78 sold out. Managers that filed in both quarters added a net 515,789 shares.
How current is this WMS institutional ownership data?: It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.

From the SEC's Form 13F data sets for Q2 2026: every 13F holdings report, matched to WMS by CUSIP. Options are left out. WMS news and filings · WMS insider trades · Top funds