The market, now 90 percent computerized with continuous trading, has become more inviting to outsiders.

Roman empire had continuous trading connection with this region.

In 1988, the exchange introduced an electronic trading support system, and replaced the old auction model with continuous trading of listed shares throughout the day.

The intraday markets are organized by continuous trading - orders of the members are entered perpetually into the order book.

Continuous trading proceeds in specifically-designated securities (currently two ETFs, 4362 and 4363).

Advocates of active E.T.F.'s also highlight the greater liquidity afforded by continuous trading, as well as heightened transparency.

Combining the exchanges "will provide continuous trading, 24 hours a day, around the world via the Internet," said Jeffrey Sprecher, chief executive of Intercontinental.

Prominent amongst these are that virtual bidding occurs in electricity markets that are discrete, whereas most commodity markets allow for continuous trading.

While purchases of Japanese securities dealers at auctions attract much attention, those bids are just one day's snapshot of the continuous trading activity that precedes and follows the auctions.

After their initial sale, they would be listed for continuous trading on the exchange and their owners would have the option of exchanging them for shares of the underlying stocks.

One involved the move to continuous trading via computer screens and the formation of a new unified structure for brokerage firms, which will eliminate the need for the floor brokers who were on strike.

"This is a key piece in the unification of the Spanish market, in addition to introducing the concept of continuous trading," said Luis Carlos Croissier, the president of the state National Securities Commission, which was created earlier this year.

Then-NYSE CEO John Thain, who was to head NYSE Euronext, intended to use the combination to form the world's first global stock market, with continuous trading of stocks and derivatives over a 21-hour time span.

Nasdaq's move toward 24-hour trading is proceeding even though the N.A.S.D. and regulators have not fully resolved the vital issue of when companies will disclose important information like earnings releases and takeovers to investors in a world of continuous trading.