The following 1-Year Daily comparison chart has the Dow 30 plotted on as the baseline. You can see that the SPX, NDX & RUT have, for the most part, outperformed the Dow this year.
We'll see if market participants are willing to keep buying into riskier assets in the NDX and RUT (since they're currently outpacing the SPX), or whether money will start flowing back into the larger-cap stocks.
My own feeling is that if (big) money starts fleeing the NDX and RUT (risk), we could, finally, see the SPX and Dow (and other world markets) follow...especially, emerging markets, Japan and China. So, I'd watch for any signs of fresh, large-scale dumping of "risk" on this comparison chart.
With the VIX currently elevated and sitting just above major support (the zone between 20.00 and 25.00), we could, very well, see some large-scale risk-dumping occur (with continued wild, volatile price swings) before markets settle down (when the VIX falls back below 20.00).