Shares of AllianceBernstein (AB) have been strong performers lately, with the stock up 3.6% over the past month. The stock hit a new 52-week high of $35.5 in the previous session. AllianceBernstein has gained 11.8% since the start of the year compared to the 12.9% move for the Zacks Finance sector and the 15.8% return for the Zacks Financial - Investment Management industry.What's Driving the Outperformance?The stock has an impressive record of positive earnings surprises, as it hasn't missed our earnings ...