Have you been paying attention to shares of United Airlines (UAL) ? Shares have been on the move with the stock up 40.8% over the past month. The stock hit a new 52-week high of $89.6 in the previous session. United Airlines has gained 116.8% since the start of the year compared to the 5.3% move for the Zacks Transportation sector and the 36% return for the Zacks Transportation - Airline industry.What's Driving the Outperformance?The stock has an impressive record of positive earnings surprises, as it hasn' ...