Are Delta Air Lines Stock Investors Happy, or Did They Miss Out?

Despite mixed performance relative to the market over the last few years, the airline stock is set to fly higher.Delta Air Lines (DAL 0.27%) stock has underperformed the S&P 500 (^GSPC +0.54%) over the last five years and the last year, but has beaten it in the previous three years. Still, the key question isn't so much where a stock has come from -- it's where it's going.On that basis, Delta Air Lines is one of the best stocks in the transportation sector, not least because it's likely to climb a wall of w ...