Regression to the mean
The market is heading into dangerous waters. Sentiment has become skewed wildly bullish and historically the market hasn't performed well during earnings season when entering at new 52 week highs.
One of the few principles that never fails is that all market eventually regress to the mean. That one you can take to the bank. Usually the further anything stretches the harder it snaps back.
It looks like the market desperately wants to reach the 1200 level but in doing so it will have stretched further above the 200 day moving average than at any point during the middle and final leg of the prior bull market.