This has been a busy week for Delta (DAL). The company held its annual investor day on Wednesday morning, after announcing a $360 million deal to buy a 49% stake in Virgin Atlantic from Singapore Airlines (SINGF.PK) on Tuesday. As part of the Virgin Atlantic investment, Delta and Virgin Atlantic also intend to apply for antitrust immunity for a joint venture in the transatlantic market. Delta's consistent record of improvement over the past few years comes through clearly in the slide deck from the investor presentation. Moreover, Delta's recent strategic initiatives position the company well to deliver further profit growth over the next 2-3 years. With the company trading for less than...