This airline giant can fly even higher. Shares of United Airlines (UAL 0.17%) surged to their highest level since early 2020 following the company's latest quarterly update in mid-October. The global carrier beat its own bottom-line expectations, with management citing strong demand during a "prosperous" summer flying season. Shareholders have a lot to be cheering about, with the stock up 110% over the past year. On the other hand, investors sitting at the gate may be wondering if it's too late to board thi ...