Materion Corp. (MTRN) Bounced Back in Q3

Heartland Advisors, an investment management company, released its “Heartland Value Plus Fund” third-quarter 2025 investor letter. A copy of the letter can be downloaded here. The third quarter proved to be robust for small caps, signaling improved demand dynamics. The Russell 2000® Index was up 12.39% in the quarter, outperforming the S&P 500 Index, which rose 8.12%. The fund returned 8.51% in the third quarter compared to a 12.60% gain for the Russell 2000® Value Index. In addition, you can check the fund’s top 5 holdings to determine its best picks for 2025.

In its third-quarter 2025 investor letter, Heartland Value Plus Fund highlighted stocks such as Materion Corporation (NYSE:MTRN). Materion Corporation (NYSE:MTRN) is an advanced engineered materials manufacturer. The one-month return of Materion Corporation (NYSE:MTRN) was 3.07%, and its shares gained 11.67% of their value over the last 52 weeks. On October 10, 2025, Materion Corporation (NYSE:MTRN) stock closed at $118.10 per share, with a market capitalization of $2.448 billion.

Heartland Value Plus Fund stated the following regarding Materion Corporation (NYSE:MTRN) in its third quarter 2025 investor letter:

"Our top performer for the quarter was Materion Corporation (NYSE:MTRN), a vertically integrated producer of high-performance advanced engineered materials based on beryllium, a rare metal that is one-third lighter than aluminum but has six times the stiffness of steel.

MTRN has been taking several steps to improve operations and bolster margins during a slower overall period for some of its end markets, such as autos, industrials, and life sciences. Over the past year, as demand has remained subdued, management divested its unprofitable Architectural Glass business in New Mexico while expanding high-margin capacity for advanced semiconductor capabilities in South Korea. The stock recently experienced outsized strength post tariff fears as Materion produced record margins with guidance for accelerating growth as a variety of end markets have visibility to a sustained rebound in demand.

Though the stock has bounced back, it’s still trading at an attractive price. If MTRN shares reach our target, that would still be a just 1.7x FY 2026 sales and 12x EBITDA."

Materion Corporation (NYSE:MTRN) is not on our list of 30 Most Popular Stocks Among Hedge Funds. According to our database, 24 hedge fund portfolios held Materion Corporation (NYSE:MTRN) at the end of the second quarter, up from 22 in the previous quarter.  While we acknowledge the potential of Materion Corporation (NYSE:MTRN) as an investment, we believe certain AI stocks offer greater upside potential and carry less downside risk. If you're looking for an extremely undervalued AI stock that also stands to benefit significantly from Trump-era tariffs and the onshoring trend, see our free report on the best short-term AI stock.

In another article, we covered Materion Corporation (NYSE:MTRN) and shared the list of best magnesium stocks to invest in. In addition, please check out our hedge fund investor letters Q3 2025 page for more investor letters from hedge funds and other leading investors.

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Disclosure: None. This article is originally published at Insider Monkey.