Avantor (AVTR) Slid on Lower Than Expected Guidance

Longleaf Partners, managed by Southeastern Asset Management, released its first-quarter 2026 investor letter. A copy of the letter is available to download here. The Fund returned -4.46% in the quarter, compared to the S&P 500’s -4.33% and the Russell 1000 Value Index’s 2.10% return. The year began similarly to the second half of 2025, with rising […]