Advanced Drainage Systems WMS Institutional Ownership

Updated Oct 11, 2026

Advanced Drainage Systems, Inc. (NYSE:WMS) was held by 552 institutional investors that filed 13F reports for the quarter ended June 30, 2026.

• These investors held 90.88% of Advanced Drainage Systems' outstanding shares at the end of Q2 2026, up from 89.22% in Q1 2026.
• Total shares held in Advanced Drainage Systems rose 0.25% from Q1 2026, while the number of holders rose 15.48% from Q2 2025.
• Of these 552 holders, 259 added to their positions, 208 reduced their stakes and 85 left their positions unchanged.
• Altogether, institutional holders owned 69.55Mn WMS shares at the end of Q2 2026, up 174.29K from the prior quarter and down 1.32Mn from a year earlier.
• BlackRock, Inc. was the top holder of Advanced Drainage Systems as of June 30, 2026, with 7.47Mn shares, or 9.76% of shares outstanding.
• Among holders that already owned Advanced Drainage Systems, the biggest buyers in Q2 2026 were First Trust Advisors LP (+616.7K shares), BAMCO Inc (+389.28K shares), Balyasny Asset Management L.P. (+339.86K shares), Marshall Wace, LLP (+307.57K shares) and Qube Research & Technologies Ltd (+293.41K shares).
• The biggest cuts to WMS positions during Q2 2026 came from Pictet Asset Management Holding SA (-1.08Mn shares), Adage Capital Partners GP, L.L.C. (-400K shares), Wellington Management Group LLP (-222.74K shares), Baillie Gifford & Co (-212.05K shares) and Westwood Holdings Group Inc (-185.34K shares).
• Per Business Quant data, the 10 largest holders of Advanced Drainage Systems at the end of Q2 2026 were BlackRock, Inc. (7.47Mn shares), Vanguard Portfolio Management LLC (3.71Mn shares), Vanguard Capital Management LLC (3.4Mn shares), State Street Corp (2.69Mn shares), First Trust Advisors LP (2.66Mn shares), UBS Asset Management Americas (2.35Mn shares), Impax Asset Management Group plc (1.85Mn shares), Baillie Gifford & Co (1.84Mn shares), American Century Companies Inc (1.63Mn shares) and Morgan Stanley (1.39Mn shares).