Heartland Advisors Inc. reduced its stake in Materion Co. (NYSE:MTRN – Get Rating) by 25.6% during the fourth quarter, according to its most recent filing with the SEC. The fund owned 76,622 shares of the basic materials company’s stock after selling 26,309 shares during the quarter. Heartland Advisors Inc. owned 0.37% of Materion worth $6,705,000 […]