Have you been paying attention to shares of Rush Enterprises (RUSHA) ? Shares have been on the move with the stock up 15.3% over the past month. The stock hit a new 52-week high of $60.55 in the previous session. Rush Enterprises has gained 16% since the start of the year compared to the 20.7% move for the Zacks Retail-Wholesale sector and the -1% return for the Zacks Automotive - Retail and Whole Sales industry.What's Driving the Outperformance?The stock has an impressive record of positive earnings surpri ...