Can the stock bounce back?It's been a challenging time for some discount stores. After rival Dollar General (DG 2.70%) saw its shares lose a third of their value late last month following disappointing results and guidance, Dollar Tree (DLTR -2.88%) didn't fare much better when it announced its own fiscal Q2 results; its stock fell by more than 22% in the session that followed. Let's take a close look at Dollar Tree's earnings report and guidance, and see if investors should buy this dip. Lowered guidanceAf ...