In my posts, I have frequently emphasized that large market participants dominate the equity index markets and control its movement. My trade-by-trade analysis suggests that the largest 3-4% of trades (those over 100-200 contracts each in ES) account for well over half of the total volume in that market. Because volume correlates very highly with price volatility, the presence or absence of large traders in the marketplace is an important determinant of opportunity for the intraday trader.
Above we have a demonstration of how size controls the markets. The chart represents the S&P emini futures (blue line) over the past month. The red line is a cumulation of the ES price changes over the month that included only those one-minute periods that traded on twice (or more) the average volume expected for that time of day. In other words, the red line is price change solely attributable to time periods in which size has hit the market. These high volume occasions accounted for only about 11% of the minutes in the trading day.
The two lines correlate almost perfectly: .96. Essentially all of the movement in the ES can be accounted for by the small number of periods in which large participants have entered the market. When large locals and institutions are not in the market, the market--for all practical purposes--goes nowhere.
Many market indicators and technical analysis formulations treat each time period during the day as equivalent. An alternative--and promising--strategy is to separate signal from noise by analyzing only those time periods in which large participants are present.
My data suggest that fully half of all ES trades are one and two lots that only account for 3% of total market volume. In a very real sense, over half of everything that occurs in the equity indices doesn't matter. The key is focusing on the trades--and traders--who do move the markets.