Armstrong World Industries, Inc.
A maker of suspended ceiling systems, specialty walls, and exterior metal panels for commercial buildings, sold to distributors, home centers, and contractors. It began in 1860 as a one-room cork-cutting shop in Pittsburgh, where founder Thomas Armstrong stamped his name on every cork and delivered his first orders by wheelbarrow. That cork business later grew into the company that invented acoustical ceiling tiles, the suspended ceilings found in offices and schools today.
Estimated from filings — the split-adjusted price range over the quarters each manager built the position. A range, not a fill price; 13F reports a quarter-end snapshot, not a trade date.