Below there is a chart aggregating the SP500 December returns from 1982 to 2013.
Keep in mind, no bull market ends with a high momentum top.
The sentiment is still extreme, which implies the risk of a correction, and in this context we said and still think that the recent weakness/pullback was just the beginning of a bigger distributive pattern, where at least one more rally leg would be missing to form a potential top of a larger degree.
The market internals showed imbalanced on the on Vol NYSE vs Nasdaq
The SP500 is recovering from the drop this morning.