Since 07, there are quite a # of outlier cases that run straight up 20+ pts, not filling the upside gap, then later in the day, sell all the way back down to fill the gap. Those days usually form a spike and ledge by noon.
Today looks more like the classic ones - gap not filled, run up a little and then consolidate.
Since there is no big spike up, by going sideway, it will grind the momentum overbought condition to neutral by afternoon, giving the market more room to go up.