Heartland Advisors, an investment management company, released its “Heartland Mid Cap Value Fund” third-quarter 2025 investor letter. A copy of the letter can be downloaded here. The portfolio increased 1.63% in the quarter, lagging behind the Russell Midcap® Value Index’s 6.18% gain. Stock selection was the primary contributor to the underperformance. The market witnessed the trends from Q2 accelerate, with optimism about the AI boom and rising electricity demand pushing large- and mid-cap growth stocks to ...