Have you been paying attention to shares of Builders FirstSource (BLDR) ? Shares have been on the move with the stock up 7.8% over the past month. The stock hit a new 52-week high of $208.16 in the previous session. Builders FirstSource has gained 19.7% since the start of the year compared to the 8.1% move for the Zacks Retail-Wholesale sector and the 9.5% return for the Zacks Building Products - Retail industry.What's Driving the Outperformance?The stock has an impressive record of positive earnings surpri ...