Aw, come on syl. Look at a 60-minute chart and you'll see it turned down yesterday AM. So did the 120-minute charts. If those want to hit bottom, it takes a good day or more of selling to get there.
Furthermore, we hit some levels on some indicators this AM that showed a high probability of a close at or near the lows today. When we dropped below 1374 COMP, there was also a strong chance we'd test the lows from last week because the uptrend failed.
We test overhead resistance. When it fails, we test underlying support. It's really pretty simple. We failed at restistance yesterday, the charts turned down, and we went hunting for underlying support to test.