Concerned that exchange consolidation could raise your trading costs? Don't be. Another wave of electronic communication networks is popping up to challenge the big boys, and their early success suggests that pricing power in the stock trading business is a thing of the past. With their low prices and rising volume, these electronic platforms are emerging as a new threat to the public exchanges -- which is ironic considering that both the NYSE ( NYX) and Nasdaq ( NDAQ) swallowed ECNs to achieve their current scale. Buzz about new networks started to circulate in securities' circles last week, as traders looked for ways to protect themselves in case the established exchanges tried to charge more for their services. The new ECNs leverage several advantages, the main one being the virtually nonexistent barriers to entry in the business they are pursuing. New electronic platforms are easy to start up and, despite their relative obscurity, can quickly become a viable alternative in this elastic market. "It is very cheap to buy a computer, put in a couple of communication lines, and you are in business," says James Angel, associate professor of finance at the McDonough School of Business at Georgetown University. "Pure trade matching has become a low-cost electronic commodity. Without entry barriers, it becomes a competitive, cut-throat business." Rumors about possible mergers sparked a run-up in the shares of major exchange stocks two weeks ago. Stock markets from New York to Germany were dragged into the speculation. Since the drama has cooled, however, many of the big exchange stocks ticked down, and real probing of the industry has begun. Shares in the Nasdaq ( NDAQ) declined $3.22, or 7.4%, last week to $40.56. The NYSE Group ( NYX) fell $8.28, or 9.5%, to $78.57. Representatives from both companies declined to comment for this story. In pre-electronic times, consolidation would have given the exchanges an advantage. Fewer players in the industry would have meant more pricing power. If there was a situation where there were two main exchanges -- the Nasdaq and the NYSE, for example -- per-trade prices could become very expensive.