Key TakeawaysMicron shares moved higher in early trading Tuesday, gaining ground for the fourth straight session, ahead of the chipmaker’s eagerly anticipated fiscal fourth-quarter earnings report, due after Wednesday’s closing bell.The stock has formed two distinct troughs between August and September, potentially marking a double bottom in the chipmaker’s shares.Investors should monitor important lower price levels on Micron's chart around $87 and $79, while watching key higher price levels near $109 and ...