I know a lot of my trader friends will sell for a loss before year end so they can leverage the loss for tax purposes then buy the stocks right away in January...
skeet, like Johnny mentioned and was right on is that some sell at the end of the year so they can offset their gains they may have had on others throughout the year that they will owe taxes on. Many will in the month of December (especially the last week) sell their Pennies they hold that might be at a loss to counter their gains and reduce their tax liability. Cuz of that the last couple of weeks in December can see some downward pressure on many Pennies out there as people sell. Hope this makes sense.
News 
Market Data 
Discover 
