The opening range concept mentioned in the previous few posts can also be used intraday. Below is a chart of the S&P 500 Emini futures. The opening range is calculated using the high and the low of the first 15minutes of the day. To calculate the extensions you simply add the range to the high for the first 15minues, and subtract the range from the low of the first 15minutes.
S&P 500 Index Emini Futures 2/4/09(click to enlarge)
On days when there is not a strong momentum trend, these levels act like targets and support and resistance. Almost like they are magnets that prices are pulled to, even if it is for a short time.
Below is a chart of the Five Year Treasury Note Futures, again the prices seemed to be attracted to these levels.
5 Year Treasury Note Futures 2/4/09 (click to enlarge)