by Calculated Risk on 5/06/2010 06:53:00 PM

Usually I focus more on economics, but ...

Via Reuters:

Nasdaq Operations said it will cancel all trades executed between 2:40 p.m. to 3 p.m. showing a rise or fall of more than 60 percent from the last trade in that security at 2:40 p.m or immediately prior.

This needs an explanation ...