Shares of General Motors (GM) have been strong performers lately, with the stock up 14.9% over the past month. The stock hit a new 52-week high of $55.38 in the previous session. General Motors has gained 53.3% since the start of the year compared to the -1.5% move for the Zacks Auto-Tires-Trucks sector and the 5.4% return for the Zacks Automotive - Domestic industry.What's Driving the Outperformance?The stock has a great record of positive earnings surprises, as it hasn't missed our earnings consensus est ...