Lots of possibilities here. The market was extremely overbought up to now and finally some of that pressure was released. For most indices it tapped that declining trendline and turned around. 60 min frames issued sell around mid day
1. Retest lows because the rubber band has been stretched so quickly for so far. As a short, would look for volume spikes to confirm 50%. If this happens I would expect it to be a violent move down.
2. Consolidate for move higher 25%
3. Gap up and just shrug off today's action 25%
Some indexes like QQQ and SPY held up fairly well. Others like DIA, NYA, and the usual leading index IWM, issued fairly bearish reversal candles. One issue was that volume was weak but that didnt stop us from taking a big fall on Oct 7, the day after we had a similar day such as today.