What happened 

Shares of 3D printing company Stratasys (SSYS -0.24%) jumped as much as 10.5% in trading on Tuesday, after its biggest competitor, 3D Systems (DDD 1.42%), reported earnings. This performance comes less than a week after Stratasys itself reported outstanding earnings

So what

3D Systems' revenue was up 44%, and it earned an adjusted $0.12 per share, more than double what Wall Street analysts expected. This result follows 25% revenue growth from Stratasys and a loss of just $0.02 per share.

3D printed part being made in a printer.

Image source: Getty Images.

Investors seem to be seeing a sharp improvement in the performance of 3D printing stocks overall right now. If both Stratasys and 3D Systems can grow and improve the bottom line, maybe both will be profitable growth stocks in time. The industry has had fits and starts but seems to be in a more mature place than it was a decade ago, which is helping stocks right now. 

Now what

What investors will want to look for long-term is for these growth and profitability trends to continue. 3D printing companies have fought with printer prices that are falling faster than the increase in volume of sales, which has resulted in stagnating or declining revenue. If that trend reverses, it could be a good sign. I'm skeptical until we see more quarters of growth, but right now investors think the worst is behind the 3D printing industry.