Heartland Advisors released its third-quarter 2025 investor letter, showing strong performance in small caps with the Russell 2000® Index up 12.39%. The fund returned 8.51% compared to a 12.60% gain for the Russell 2000® Value Index. Materion Corporation (NYSE:MTRN) was highlighted as a top performer, with shares closing at $118.10 on October 10, 2025.

In its investor letter, Heartland Value Plus Fund praised Materion Corporation (NYSE:MTRN) as a top performer, citing its production of high-performance materials based on beryllium. Materion Corporation (NYSE:MTRN) saw a one-month return of 3.07% and a 11.67% increase in share value over the last 52 weeks.

While Materion Corporation (NYSE:MTRN) is not among the 30 Most Popular Stocks Among Hedge Funds, 24 hedge fund portfolios held it at the end of the second quarter. Heartland Advisors see potential in Materion Corporation (NYSE:MTRN) but believe certain AI stocks offer better upside potential and less downside risk.

Read more at Yahoo Finance: Materion Corp. (MTRN) Bounced Back in Q3