Known for its extremely bearish stances, research firm Citron Research has come out with a report detailing a long list of red-flag reasons for investors to be bearish on 3-D printing company 3D Systems (NYSE:DDD). Shares of the company are down around 17% over the past five days, initially selling off as the overall market pulled back this week, but really accelerating once this report came out.

Among other things, the report highlights growth problems with the company, saying that acquisitions cannot maintain this pace, that the company's recent acquisitions have been uninspiring, and that 3D Systems' organic growth rates are misleading. The report also discusses poor reviews of working for the company from employees, as well as an R&D budget that is spread too thin over too many projects, leaving the company a jack of all trades, master of none. By comparison, the report has several positive things to say about competitor Stratasys (NASDAQ:SSYS).

In this video, Fool industrials analyst Blake Bos takes a good look through the report, and tells investors what he thinks of 3D Systems today, and of investments in the 3-D printing sector as a whole.