sentrade, who tracks the daily sentiment in the SPX, sent out the following tweets.
"S&P increased from 37% to 50% Bulls today. A daily increase of 13% Bulls is extreme and rare."
"Since the 2009 lows, S&P increased by 13%+ Bulls in a day five times"
"Those dates were: 05/10/10, 05/27/10, 10/27/11, 06/29/12, and 01/02/13"
What I find most interesting is that, expect for the 1/2/13 date, each large up thrust was completely reversed in 8 trading days or less. History suggests that today's move will not hold.