Trying to determine the level a price Correction or Retracement will move to is difficult. There are tools and methods that go some way in helping: Fibonacci Fan, Gann Fan, Channel Lines, Pitchfork, Fibo Levels, counting bars and Wave counts that when combined aid in determining that part of the price movement is complete. On the chart below the first fibo level Blue #1 can be drawn when the first Impulse Wave is believed to have completed. That fibo can be stepped upward at several points in an uptrend, remaining a reliable constant throughout the larger movement. When the main wave is thought to have topped via Blue #1, bar count and a possible Reversal formation (EW 'AB') combining to indicate a Correction is expected, then the Grape colored fibo can be drawn immediately between the HL. On such 'major' waves the fibo often performs better when drawn from HH to LC for Corrections and LL to HC for Retracements. Once the first down wave has formed, the Red #1 fibo can be drawn which as can be seen provides different information than the larger Grape fibo, but is used to project price level targets as is Blue #1. What can also be drawn is any of the several trend tools such as the Fibo Fan. Because the fan pivots from its fulcrum starting point, as the wave progresses the fan can be moved and as it and price bars intersect fibo levels, and possibly another trend tool etc, may produce a good end of move signal. The Standard Error Channel functions in the same way as the Fan and can remain useful for a long time as the price progress, as can be seen on the Wave C Correction and Reversal formation. Also used on the new Impulse Wave where the Blue #1 fibo has been stepped to, the Aqua colored SEC shows how the Blue SEC looks after readjustment with price progression. How one trades Cs and Rs is a matter of whether one's trying to scalp the mini-waves or trade the longer time period where one presumes 'A' will end for instance. While the HL is obviously important, Closes have more significance for me, but Stops if used have to be determined by H/Ls to allow for scalps or early entries when Reversal/bases often form prior to trend change. Other Momentum or Stochastic etc Indicators may also assist as well as Donchian Channels etc. Two additional chart samples from Advanced Get and Dynamic Trader can be viewed at: http://www.moneytec.com/forums/_showthread/_threadid-7978/_s-c8e35b702fc70461c7099f89b4fecbba where their program specific tools also go some way in determining Correction/Retracement levels.