What happened Shares of 3D prototyping company Proto Labs (NYSE: PRLB) joined a broad rally among 3D printing stocks of all stripes Thursday, rushing ahead to close the day up 13%. So what In the absence of any other news, Proto Labs' share price strength appears to trace back directly to preliminary fourth-quarter earnings results published by 3D printer maker 3D Systems (NYSE: DDD) this morning. In that announcement, 3D Systems noted that sales for the fiscal fourth quarter seem likely to land at least 21% higher than analysts had forecast. What's more, the company says it might finally break a string of quarterly financial losses that has stretched back, uninterrupted, for four straight years. A 3D printer. Image source: Getty Images. Now what So an announcement like that might make investors in other 3D printing stocks feel just a bit more optimistic about their own chances. And even if 3D Systems' good news doesn't spread to other stocks in the sector, here's another reason for optimism: Unlike 3D Systems, Proto Labs itself has been profitable for every year of its existence as a publicly traded company. And that's an even better reason to like the stock than anything 3D Systems might have to say. 10 stocks we like better than Proto LabsWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Proto Labs wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of November 20, 2020 Rich Smith has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Proto Labs. The Motley Fool recommends 3D Systems. The Motley Fool has a disclosure policy.Source