Hey guys/girls,

I'm looking into establishing a high and low for the first 30min of trading (after open)
so from 10:00 to 10:30.

The idea is to establish a support and resistance level, which will trigger a buy on breakout up and sell on breakout down.

However, and this is my current problem:

I'd like to only do the above, if a range has been developed, ie:

If the price simply steadily moved up from 10:00am to 10:30, I am not really interested.
But if the price moved up and down quite alot, in this range (for first half hour), then these support/resistance levels are definitely more significant, and I'm interested.

What I'm kind of wondering, is whether there's a way of establishing this is-signficant/not-significant, in either code or an excel sheet (bloomberg data enabled)? i was thinking perhaps a fourier analysis but this seems a bit over the top ... is there another way of distuingishing a signal that moved up and down alot in a range from one that hasn't? (i'm thinkin this cant be rocket science but my brain is failing me right now)

Help much appreciated!