This button was manufactured in the growing years of the Chicago Mercantile Exchange, a few years before the CME and the Chicago Board of Trade formed an alliance to expedite transactions.
The button features the phrase ED FUTURES OPEN INTEREST TO 2 MILLION with ED standing for Eurodollar. Eurodollar futures are a way for companies and banks to lock in an interest rate today, for money it intends to borrow or lend in the future. They are the most widely traded futures in the world (Wikinvest*).
This button helps to document the recent history of the Chicago Mercantile Exchange, one of the city's most important financial institutions. Advertising Eurodollar open interest of two million was a way for CME to broadcast its growth to the world. Founded in 1898 as the Chicago Butter and Egg Board, the Chicago Mercantile Exchange (CME) has revolutionized trading with innovative products and systems. In 1972, CME introduced futures on seven foreign currencies, including the British pound, Deutsche mark, and Japanese yen. Since then, CME has become the world's largest regulated marketplace for foreign exchange trading. Buttons like this one advertised the growing CME to the world as a premier trading exchange.