Don't know and it makes little sense for now. Vol. has picked up dramatically since late morning and it looks like 2 million shares plus will be traded today. All of this when the markets, as a whole, are starting to get a bit deeper in the red which is not unusual for a summer Friday afternoon when the traders close shop early and head to the beaches or golf courses or whatever. Be careful of Monday as the GDP numbers of China are released. Any weakness below 7.5% could spell a miserable day Monday for the markets, but I don't know if that will have an effect on cldx.
My guess is that there is something big brewing and that could mean merger or aquisition. Again, the volumn this afternoon is strangly strong.