Advanced Drainage Systems (WMS) Soared as Multiple Tailwinds Align

Core Insights - The BBH Select Series - Mid Cap Fund experienced a total return decrease of -0.9% in Q3 2025, underperforming the Russell Midcap Index, which returned 5.3% [1] - Year-to-date, the Fund's total return is -1.8%, compared to the Index's 10.4% [1] - The third quarter saw a continuation of the low-quality rally that began late last year, gaining momentum throughout 2025 [1] Company Highlights - Advanced Drainage Systems, Inc. (NYSE:WMS) is noted as a significant contributor to the Fund's performance in Q3 2025 [3] - The stock of Advanced Drainage Systems, Inc. had a one-month return of -2.42% but gained 13.05% over the last 52 weeks [2] - As of December 09, 2025, Advanced Drainage Systems, Inc. closed at $144.80 per share, with a market capitalization of $11.26 billion [2]