As an addendum to Mark's (as usual) excellent comments, you may want to consider simple Wyckoff Price/Volume analysis. Trading-ranges are usually preceded by climatic action - High volume, wide price spreads closing near/at the highs, parabolic price action. This is usually accompanied by good mkt news (in a buying climax), that and the strong price action brings in the public. Mkts cycle between high-volatility (trend) and low-volatility (range/consolidation). When the trend has exhausted itself, it has to rest and absorb the previous price action and prepare itself for the next move, either up or down, which will be determined by whether there is accumulation/distribution or re-accumulation/re-distribution occurring w/in the trading-range.
For instance look at the present situation in the currency GBP futures. (You may have to click on the chart to get the full view.)
http://tinyurl.com/ycyr69
There is a very long trading-range going back to May, then from A to B a parabolic rally that breaks out of the range on expanding volume and wide spreads, most closing on the highs, w/little retracement along the way. Then on 11/30 and 12/01, the last 2 days of the rally, we see the highest vol in months, including the entire range. All taken together - a parabolic rally (which can only be sustained for so long), wide spreads, massive vol, plus the fact that we're near the extremely important psychological and technical resistance at the 2.00 mark, suggests climatic behavior. And just to show that I'm not completely full of shite, I mentioned this very pv behavior in this thread on 12/04, the day the retracement of this rally began:
http://elitetrader.com/vb/showthread.php?s=&threadid=79308&perpage=20&pagenumber=2
So now one looks at the nature of the retracement following the climax. What do we see here? Well, vol has remained strong on the reaction, which suggests at the very least that there is further downside to go. However on Fri we see massive vol on a very wide spread closing on the low, this suggests temporary climatic behavior on that reaction. Here one is trying to determine if this latest rally was what Wyckoff referred to as an Upthrust, which will result in a drop back down into the range and a continuation of the range, or a downtrend that breaks down thru it, or a Sign of Strength, which is a true breakout and the start of a new uptrend. I suspect this is not an upthrust, for one because of the time factor (it has held well) and also because of what Wyckoff referred to as Effort vs Result. Despite the strong vol on the reaction, the retracement (of A to B) thus far is quite shallow.
At this point, intraday, as of this writing, the mkt is continuing lower, and I suspect, even if we drop lower, there will be a consolidation period above that previous long trading-range where more accumulation will take place, before the mkt can significantly rally again.
Wyckoff has very specific criteria to attempt to determine what the mkt is doing, trending or consolidating, and where it is w/in that particular phase. I won't go into it too deeply here, there's just too much, but most simply, for a trading-range: There is a trend that ends w/a Buying Climax, then an Automatic Reaction (as the buyers are exhausted) - these two high/low points establish the boundaries of the ensuing range - this followed by a secondary test of the BC, followed by a series of tests of the range boundaries, these are either shallow or deep, upthrusts or shakeouts, and finally there is a positive test of the range followed by a Sign-of-Strength, a strong breakout of the range on just the kind of pv behavior we see on the GBP chart from A to B. The point at A is the shallow, positive test of the previous low at X. Note also the contracting volatility of the whole range here, as it starts off w/wide swings from May thru the beginning of Aug, then narrows from Aug to Nov. This is classic Wyckoff pv behavior of high-volatility in the beginning of the range as it first comes off the trend, then cycling to lower volatility near the end of the range as the mkt "winds itself up" in preparation for the next move.
Harold