MLM vs STLD Comparison

Martin Marietta is a leading US producer of construction aggregates, having produced roughly 200 million tons in 2025. Its aggregate reserves represent approximately 85 years of supply at 2025 production levels. Over the past several years, the company has increased its exposure to aggregates while reducing its presence in cement and downstream businesses such as concrete and asphalt. More recently, Martin Marietta expanded into an aggregate-adjacent business through its acquisition of Lhoist North America, the largest US producer of lime. The company operates across 28 states, with smaller operations in Canada and the Bahamas.

Steel Dynamics Inc operates as a domestic steel producer and metal recycler in the United States. The company's product portfolio comprises hot rolled sheet, hot rolled plate, painted sheet products, cold rolled sheet, and others. Its reportable segments are steel operations, metals recycling operations, steel fabrication operations, and aluminum operations. Maximum revenue is generated from its steel operations segment, which consists of manufacturing various steel products and numerous coating operations. Its primary sources of revenue are currently from the manufacture and sale of steel products, the processing and sale of recycled ferrous and nonferrous metals, and the fabrication and sale of steel joists and deck products.