A month has gone by since the last earnings report for United Airlines (UAL) . Shares have added about 12.8% in that time frame, outperforming the S&P 500.Will the recent positive trend continue leading up to its next earnings release, or is United due for a pullback? Before we dive into how investors and analysts have reacted as of late, let's take a quick look at the most recent earnings report in order to get a better handle on the important catalysts. Narrower-Than-Expected loss in Q1United Airlines  re ...