Below is a 1-day 1-minute percentage comparison chart of the Dow 30, S&P 500, Nasdaq 100, and Russell 2000...the Russell index was "less weak" than its counterparts (on today's action).
Below are a series of Daily charts of these 4 indices with relevant support and resistance levels marked on them...the S&P broke and closed below a major support level of 1220 today, with an impressive move and close below near-term support of 2300 on the Nasdaq...two to watch.
Price has wandered back down to levels seen around August 4th (the day before the U.S. credit rating downgrade by Standard & Poor's) on all these indices...and, in fact, down to the August 5th levels on the Russell 2000.
This tells me that these markets have not yet resolved this downgrade issue, and they are subject to further weakness until they do, and until the bulls commit to buying on convincing volumes.