5. Metal 3D printing continues to be a high-growth area of the industry. Wohlers noted that the metal 3D printing industry, in terms of units, grew by 54.7% annually in 2014, and in total, 543 metal 3D printers were shipped throughout the year. This growth suggests that metal 3D printing is becoming more widely accepted as a viable option for one-off and lower-volume manufacturing applications. As manufacturers figure out new applications for metal 3D printing, it's reasonable for investors to expect this trend to continue growing in the years ahead.