What Constellium SE told the SEC could break it.

Constellium converts aluminum into rolled products, extrusions and structural components, so its cost base is dominated by aluminum prices. In 2025 cost of sales rose 14% to $7,262 million, driven primarily by an 18% increase in raw materials and consumables from higher metal prices (and higher volumes). Aluminum pricing has three drivers — the LME price (macro supply/demand), regional premiums such as the U.S. Midwest Premium (which moves with tariffs, warehousing and transport), and product premiums — and its processing is energy-intensive, with some long-term sales contracts carrying energy-price indexation. Sharp moves in any of these, when not fully or promptly passed through, compress margins.

“This increase in Cost of sales was primarily driven by an 18% increase in raw materials and consumables used primarily as a result of higher metal prices and higher sales volumes .”

Constellium's revenue is concentrated in a handful of large aerospace, packaging and automotive manufacturers. Its two largest customers together accounted for $1,795 million of 2025 revenue ($943 million and $852 million respectively) — each individually exceeding 10% of the Group's roughly $7.9 billion in revenue — and its ten largest customers represented about 56% of revenue. These are long-term (often multi-decade) relationships, but loss of, a program cancellation by, or a sharp build-rate decline at either of the two largest customers would have an outsized impact on revenue and capacity utilization.

“Revenue from sales to the Group's two largest customers was $ 1,795 million ( $ 943 million and $ 852 million respectively) for the year ended December 31, 2025 .”

Constellium operates globally (United States, France, Germany, Switzerland, Czech Republic, Slovakia, Spain, China, Canada and Mexico) and moves aluminum products across borders, exposing it to tariffs and trade conditions. The impact is realized: following 2025 tariff announcements, North American aluminum prices (LME price plus the Midwest Premium) rose sharply, and its Automotive Structures & Industry (AS&I) segment's Adjusted EBITDA declined partly due to an unfavorable impact from tariffs. Continued tariff and trade uncertainty affects regional premiums, input costs and demand, and the company says it develops contingency plans to address potential disruptions.

“Following the tariff announcements in 2025, market aluminum prices (LME price + Midwest Premium) have risen sharply in North America, and certain spot scrap aluminum spreads have improved from previous historically tight levels.”