The claim is broadly correct. CME Group’s official COMEX copper contract specifications say copper futures are quoted in U.S. cents per pound, which supports the first half of the statement. A German Bundestag report on raw-material contracts says such contracts were usually concluded on a dollar basis, but in some cases also on a DM basis, and the Deutsche Bundesbank confirms the Deutsche Mark was Germany’s currency from 20 June 1948 until the end of 2001. A FRED/NBER historical series for copper in Berlin records prices in marks per 100 kilograms, i.e. German-mark pricing by weight, which is consistent with the “DM per tonne” formulation after unit conversion. So the wording is a reasonable summary of historical copper market quoting conventions, not a literal exchange contract specification. Sources: CME Group copper futures contract specifications (https://www.cmegroup.com/trading/metals/files/copper-futures-and-options.pdf); Deutscher Bundestag, Drucksache 7/4479 (https://dserver.bundestag.de/btd/07/044/0704479.pdf); Federal Reserve Economic Data / NBER Macrohistory Database, “Wholesale Price of Copper for Berlin, Germany” (https://fred.stlouisfed.org/data/M0416ADE00BERM370NNBR); Deutsche Bundesbank glossary entry for Deutsche Mark (https://www.bundesbank.de/dynamic/action/en/homepage/glossary/729724/glossary?contentId=653630&firstLetter=D).