Shares of 3D-printer maker Stratasys (NASDAQ:SSYS) jumped in Tuesday trading, closing the day up 12.5%. You can thank Stifel Nicolaus for that. So what Stifel initiated coverage of Stratasys stock with a buy rating this morning, assigning the stock a $40 price target. The analyst explained that, "[W]e like the company's simplified strategy, as it takes a step back to focus on maximizing its leading position in the polymers market" -- as opposed to newer 3D-printer makers such as Desktop Metals, which are focusing on the construction of hardier all-metal objects from additive manufacturing. "While the growth outlook for the polymer industry may be lower than that of metals," noted Stifel in a note covered on StreetInsider.com, Stratasys's "mature" business "can leverage its existing infrastructure, including its best-in-class reseller network [to sell] refreshed and new technologies" to its existing customer base.