It's busy week for earnings with 142 S&P 500 companies set to report. On Tuesday, notable reports include Dow components Dupont (DD), Caterpillar (CAT) and Procter & Gamble (PG), all reporting before the bell. After Tuesday's close, tech heavyweights Apple (AAPL) and Yahoo (YHOO) release their Q4 earnings results. Investors will also be keeping an eye on the release of blue chip, AT&T (T). On tap on the economic calendar, durable goods orders numbers for December are set to be released in the morning, along with the Case-Shiller Home Price Index for November, followed by January's Consumer Confidence Index.