Thank god for program trading because it probably saved the market from a really bad day. Here's a 2-day, 5-minute chart that shows today's action. Notice the really big bounce we had at the end of trading. Also notice it occurred on really heavy volume. This is what program trading looks like.
However, look at the daily chart and you'll see the market is still clinging to the 200-day SMA. Also notice the market traded below the 200 SMA for a period today. That indicates there are strong market forces that want to drive the index below that crucial support line.
