In the following video, Motley Fool analyst Blake Bos takes a look back at the first two months of 2013 to talk about two major movers so far this year. He discusses Netflix (NASDAQ:NFLX) and its unbelievable 104% growth since the beginning of the year, noting its major recent achievements, but he also tells us the things about its business model that make him nervous. Blake also examines Stratasys (NASDAQ:SSYS), down 22% for the year, and tells 3-D printing investors what he'll be looking for to know if this is a value buy at its current price, and why you may want to spread your investments into this sector over several companies at the moment.