First the dominant Price/Volume relationship because it has some connection to the Dow, all 4 major averages had a very dominant relationship of at least 40% of the 4 possible relationships (the Dow 50%) which was Close Down/Volume Up, in the current price configuration this is a bearish relationship, the Dow example will explain why.
Where did that volume come from? At 10 a.m. today you can make out a Shooting Star doji, it is a very bearish candle on its own and suggests churning (strong hands dumping shares to weak hands), this is where the huge volume spike occurred.
The DIA's close was $.03 from a bearish engulfing candle and technically would be a very strong Dark Cloud Cover reversal formation, opening on a gap up near the highs and closing just a few cents off the lows.
The IWM closed below resistance as seen at the red trend line, although it seems (even in 3C), that it has been trying all week to break to a new high, which technically it did Tuesday, just not a strong break.
At 10:00 this morning the IWM had its own bearish candle with a bearish engulfing candle as it briefly hit intraday highs and was rejected.
The QQQ's after yesterday's Doji Star, put in a reversal confirmation candle today, although rather small, which is almost certainly due to options expiration.
The SPY put in a bearish Harami and making it even more bearish, today's second half of the Harami pattern (known as mother with baby in Japanese) was a small bodied star, nearly a doji.
The SPY saw the same 10 a.m. Shooting star as the Dow, it briefly touched intraday highs and was rejected.