Author Bio Howard grew up in Philadelphia watching the Philly sports teams struggle for championships. He has been investing since 1989 and been a Fool since 2001. Prior to joining The Fool as a contract writer in 2019, Howard worked in the steel business as an engineer for 28 years. When he isn’t writing, he is usually out for a run, or relaxing to the music of the Grateful Dead. What happened Shares of machining, injection-molding, and 3D printing company Proto Labs (NYSE:PRLB) were up another 12% today, bringing its gains for the month of December to almost 34%. Some of the recent gains may be attributable to excitement around a special purpose acquisition company (SPAC) merger in the sector.