Brett Steenbarger writes on his site, TraderFeed, about how tradable indexes can kill a trending market.  He points out that with more indexes comes more volume and less volatility. 

Exchange traded funds continue to offer the individual more opportunity to invest in markets that might not otherwise be available to them.  Trading with ETFs increases trading volume and Steenbarger’s research indicates increased volume may not contribute to a directional market trend.  He uses historical information of SPDR (SPY) since 2000 to draw his conclusions.

The opinions and forecasts expressed herein are solely those of Tom Lydon, and may not actually come to pass. Information on this site should not be used or construed as an offer to sell, a solicitation of an offer to buy, or a recommendation for any product.