Yesterday's sell-off late in the day put heavy pressure on the support around 13515-30. We got a few spikes below the support level actually but if we are a bit generous, we can say that it held on a 15-min-timeframe:
In pre-market we're slightly up and, repeating what I said yesterday, I think as long as 13515-30 holds (spikes to yesterday's lows allowed), a rally at least to yesterday's high is likely. If the support breaks though, a close of yesterday's gap is very likely.