Exchange Wars: Snafu Pits NYSE vs. Nasdaq

Predictably, the NYSE disputed the Nasdaq's characterization.

"The specialists and our systems operated as they should in identifying the erroneous orders, posting indications, and halting and opening trading in the affected stocks to ensure fair and orderly markets," says NYSE spokesman Rich Adamonis.

NYSE officials were clearly not happy about Thursday's prolonged trading halts; Jefferies shares didn't open until 11:05 a.m. EDT, followed by AT&T at 11:28 a.m. and Wyeth at 12:34 p.m., according to Bloomberg. But the Big Board ultimately trumpeted what transpired as a victory for the floor's hybrid system, which integrates the traditional human-based auction system with computer-driven electronic trading.

Unofficial comments heard at the Big Board included, "Man over machine" and "this is what you get for non-NYSE execution" -- a reference to off-market trades which occurred in the stocks. Most notably, Wyeth continued to trade prior to the NYSE halt and the Nasdaq's subsequent canceling of orders. Other electronic marketplaces, such as the Intercontinental Exchange (ICE Quote), canceled trades on the same terms.

Essentially, the Nasdaq's perspective is that it was forced to cancel, or "break," all trades in Wyeth executed between 9:30 a.m. EDT and 10:25 a.m. at or above $58.55, because those trades were based on erroneous prices emanating from the NYSE, where the N.J.-based pharmaceutical firm's shares are listed.