What happened

For the second day in a row, shares of 3D Systems (DDD -2.10%) stock are on fire (in a good way), rising 16% in 1:30 p.m. EDT trading. But while yesterday's run-up in share price was easily tracked back to an analyst talking up 3D stock, today's news is a bit more of a "deep track."

Today, it's news out of Tesla (TSLA -4.02%) that is pushing 3D Systems stock higher.

Stock-up glowing green arrow climbs on a stock screen.

Image source: Getty Images.

So what

Specifically, it's a job posting at Tesla in which the electric car maker advertises that it's looking to hire a "highly motivated ... additive manufacturing technician ... to operate SLA/SLS/FDM 3D printing equipment in our rapidly growing Additive Manufacturing operations."  

Now, we've known that Tesla was using 3D printing to produce car parts for years. What seems to be new in this announcement is that the company is "rapidly growing" its additive manufacturing operations, more commonly known as 3D printing.

Now what

How big a piece of Tesla's manufacturing 3D printing will become remains to be seen, but Elon Musk's comments about wanting to build cars with single-piece casting speaks to the company's desire to simplify the manufacturing process with fewer parts -- and 3D printing is an ideal way to help do that.

The big question now is whether more 3D printing at Tesla directly implies more purchases of 3D printers and 3D printing materials from 3D Systems, in particular. Personally, I don't see any evidence of that in Tesla's job posting.

Regardless, 3D Systems investors seem to be reading between the lines today...and they like what they see.