Why does my stock keep plunging?

I bought China Armco Metals (CNAM) on recommendations from the Motley Fool.com..and from my research, it looked like an undervalued company, and it was amongst the favorite from the CAPS community. So I jumped in with both feet on Jan 3rd and purchased a massive amount of shares. Well ever since then, the stock has bombed hardcore! Now reports say that the company sucks and it's listed as a Strong Sell. How on Earth can a stock go from being an all-star absolute favorite amongst investors--to a total shyt shamble in only 5-6 months?