As we know we are in the seasonally bullish time of the year and the trend is strong up and has been. That said don't just automatically think that December is always a straight up month. Many times you get some consolidation during the first 2nd week etc and with the put/call indicators so extreme now we could easily see something like that. 

Therefore what I did was I took a snapshot of each Dec going back to 2006 from the daily SPX KISS chart. I placed  a vertical line on roughly the Dec 3rd - 5th area on each one to roughly correspond to our current day in the month -honestly the amount of examples is overkill but what the heck.   2013 was a good example of where the SPX has about a 2 week sideways abc like correction from about Dec 3th to Dec 17th. anyway here are all those years with the image focused on that time of the year.  again the amount of chart examples here is overkill but you can see a history of Decembers back to 2004