American Stock Exchange. The second-largest stock exchange in the U.S., after the New York Stock Exchange (NYSE). In general, the listing rules are a little more lenient than those of the NYSE, and thus the AMEX has a larger representation of stocks and bonds issued by smaller companies than the NYSE. Some index options and interest rate options trading also occurs on the AMEX. The AMEX started as an alternative to the NYSE. It originated when brokers began meeting on the curb outside the NYSE in order to trade stocks that failed to meet the Big Board's stringent listing requirements, but the AMEX now has its own trading floor. In 1998 the parent company of the NASDAQ purchased the AMEX and combined their markets, although the two continued to operate separately. In 2008, the exchange was purchased by NYSE Euronext, integrated with the Alternext European small-cap exchange, and the exchange was renamed NYSE Alternext U.S. also called The Curb.