For the week of April 20, 2015 Wall Street enters the heart of earnings season. We point out notable quarterly earnings from IBM Corp. (IBM), Morgan Stanley (MS), Halliburton (HAL), Verizon (VZ), Yahoo! (YHOO), Chipotle (CMG), Facebook (FB), Boeing (BA), AT&T (T), Google (GOOG), Amazon.com (AMZN), Microsoft (MSFT), Starbucks (SBUX), Biogen (BIIB), and American Airlines Group (AAL). On the economic front, we keep an eye on key data including existing home sales, weekly jobless claims, the PMI manufacturing index, and durable goods orders. TheStreet's Kurumi Fukushima reports in New York.