Over the counter (OTC) electronic stockmarket comprising of (1) NASDAQ National Market that lists about 4,500 of the largest US corporations, and (2) NASDAQ SmallCap Market that lists about 2,000 of the rapidly growing smaller US firms. 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).