Earnings3D Systems Corporation today preannounced results for Q4 that sent its share price tumbling, down 20% at 11AM Eastern. The topline news is good: full year revenue is expected to be around $513 million, just below the midpoint of its prior guidance. Organic revenue is up over 30% and total revenue is up over 50% in Q4.

The problem is that the company didn’t correctly forecast demand, which affected the product mix and therefore overall profitability. It’s a double-edged sword: stronger demand for professional 3D printers (good), weaker demand for consumer printers and on-demand parts (not as good, but not at all awful if you look at 30% organic revenue growth) leading to a slightly less profitable mix than expected. Add to this higher expenses for R&D, sales and marketing, and acquisition-related costs, and non-GAAP earnings per share are well below expectations at $0.83 to $0.87, versus prior guidance of $0.93 to $1.03.

CEO Avi Reichental said in prepared remarks that “we are willing to tolerate earnings reduction and even slight gross profit margin compression … to substantially accelerate our growth rate and market share. We firmly believe that these accelerated investments … position the company to double its revenue over the next couple of years on organic growth of at least 30% going forward and to achieve greater earnings power and profitability over the long term.”

The company now expects 2014 revenue in the range of $680 million to $720 million and earnings per share (EPS) of $0.73 to $0.85. The revenue range is higher than the analysts’ consensus of $671 million, but the EPS is well below a $1.27 consensus.

Wall Street is parsing this to mean that 3D printing growth can’t come with profitability, and appears worried that interest among consumers isn’t as strong as had been expected. Perhaps we won’t all have a 3D printer at home? Shocking.

3D Systems is down around 20% from the open, Stratasys (which hasn’t said a peep** but is also a 3D printing purveyor) is down 6%, and ExOne is down 7%. Even Cimatron, which has mentioned that additive and subtractive manufacturing are critical technologies going forward –and not as separate as some think– is down 10% while the overall indices are flat.

3D Systems will report final Q4 and 2013 results on February 28, 2014.

** Update: Stratasys just announced that it’s reporting Q4 results on March 3 at 8:30AM ET. No preannouncement.