The Big Board in New York is doing its impersonation of the Toronto Stock Exchange this morning. The NYSE has halted all trading until 11:15 ET.

NYSE CEO Richard Grasso explained that new software installed last night corrupted half of the market’s trading this morning, with half the market experiencing a loss of connectivity. Grasso said this was the first such problem for the NYSE in six years.

The market is reverting to its old software and will have the market back up by mid-morning. Grasso said that the market makes 250-odd software updates a year without incident, until today.

He said that with half the market out and half of it running, the exchange decided to bring the whole market down because it was unfair to the consumer to allow it to continue.