Major US over-the-counter (OTC) electronic stockmarket owned by National Association of Securities Dealers (NASD). This market now includes American Stock Exchange (AMEX) and Philadelphia Stock Exchange (PHLX), and operates London-based NASDAQ International Ltd. that allows non-US firms to be listed through American Depository Receipts (ADRs). It has two major components: (1) NASDAQ National Market listing about 4,500 top-sized US corporations, and (2) NASDAQ SmallCap Market listing about 2,000 rapidly growing smaller US firms.