To be traded, a security must list on an exchange, a central place where buyers and sellers meet. The two big U.S. stock exchanges are the esteemed NYSE and the fast-growing NASDAQ; companies listed on either of these exchanges must meet various minimum requirements and baseline rules concerning the "independence" of their boards. But these are by no means the only legitimate exchanges. Electronic communication networks (ECNs) are relatively new, but they are sure to grab a bigger slice of the transaction pie in the future.
There are auction based exchanges, which means specialists and/or floor traders are physically present on the exchangesÃ¢â‚¬â„¢ trading floors (a.k.a pits). Each specialist "specializes" in a particular stock, buying and selling the stock in a verbal auction. These specialists are under competitive threat by electronic-only exchanges that claim to be more efficient (that is, execute faster trades and exhibit smaller bid-ask spreads) by eliminating human intermediaries.
A byproduct of exchange trading is price transparency.
 Stock Exchanges
There are stock exchanges in many world capitals and major cities. These include:
For more info, see Category:Stock Exchanges
 Futures and Options Exchanges
 See Also