Never trade off the headline earning numbers, Cramer said Monday, because expectations are everything.

Take Lowe’s for example. Its stock dropped Monday morning after reporting earnings of 34 cents a share, a 2 cent miss, before the opening bell. Its revenues also fell 1.6 percent year-over-ear, and it lowered guidance. But it was a mistake to sell into the weakness, Cramer said, because this was a great buying opportunity.