They say the best ideas are the simplest, so I figured that emotion spikes drive the markets, as well as the distance that the price travells. So, because the S&P has been raising for a very long time, and every other major leg, that made new high was faster than the previous, it has spiked at the maximum momentum. The fact the recent recovery up has not outbroke the previous high, the odds are that the price will be dropping from now on.