The STO is also now in extreme territory(94.53), the Daily chart of the SPX also has the STO up at 96.24 and the Weekly chart has it at 98.99, all three are now in extreme territory signaling that this rally is on its VERY last breath and odds for a sell-off are now very high. I was thinking that things would wait until after the start of January to start breaking down to get past the end of the year window dressing, but after todays move, I do not think it will take that long, this could start breaking down as soon as tomorrow morning. A small sell-off could turn into a large cascading sell-off now, first signs will be the STO's rolling over to a sell, and a break below today's low at 1249.43.
Breadth today was weak, at only 2.23:1 advancers, on VERY low volume, 809M shares traded on the NYSE. From the look of the tape I imagine that computers accounted for the vast majority of today's action. As always, if you are long please check those stops and keep them tight, it is useless to lose a nice chunk of profit from this rally by having no stops, or stops that are set to loose.