I don't own any of PRLB but have been watching it. We are just starting to use Proto Labs for a tool and I work with a new engineer who has used them in the past. What they are doing is upending the mold making industry. You can't beat the lead time and price. I really like the company but am waiting for a pullback. You are correct, it has little to do with 3d and that is fine. 3D printing is a joke. No one in their right mind will be making high production plastic parts on a 3d printer anytime soon. It has its place, just not in PRLB's space.
Trust me, bonehead, folks with the buying power to move a stock with $1.4B market cap take the time to find out what the company does before they "bid it up." There are certainly misinformed folks why invest in PL thinking it's in 3D printing, but they're not the ones moving the price.