As can be seen from the adjacent chart, MCX copper had tumbled down in a channelised manner. The third leg of the fall had reached the lower channel line. The base metal had also tested a medium-term rising trendline. At these crucial supports bulls had rushed in to provide support to the red metal. Consequently, copper has entered a pull back mode. The pull-back is breaking up into waves of lower degrees and is unfolding in a channelised manner. The daily momentum indicator has given a fresh buy signal. The key resistance is at the swing’s high of Rs420.20; beyond that Rs431 will be the target, ie the channel target. A key support is at Rs411 whereas a major support is at Rs405.