Friday's selling raises the possibility of a head-and-shoulder reversal in the S&P and Dow. Shorts are likely to use Friday's high to measure risk for such a possibility. Bulls can look to Friday's low volume as a measure of weak bullish strength, and the successful defense of the 50-day MA. A move to angled neckline support looks likely for the coming week.

The Nasdaq is at risk of posting a new lower high, which will open the possibility for a new downward channel. On-Balance-Volume finished with a 'sell' trigger

The Russell 2000 continues to shape a broader handle. The 50-day MA is unlikely to play as support given how it failed last week, but the 200-day MA - given its proximity to newly defined handle support - might prove a better long opportunity.

For next week, look for further downside. Bulls can look to the upside gap support from Wednesday to lean on. A bearish head-and-shoulder will be negated on a move above December's highs.