Why do some stocks trade in the single digits? Often a stock is cheap because it's a loser company, and the market has priced it accordingly. It's always dangerous investing in subpar penny stocks.
On the other hand, the market is not omniscient. Sometimes stocks you want to own are surprisingly cheap. For instance, if a strong company has a really bad year because of COVID-19, its stock price can be hammered. That's what happened to shares of Rolls-Royce (OTC: RYCEY).
Or a micro-cap biotech can have some amazing news and the market is oblivious. I think that's the situation with Pieris Pharmaceuticals (NASDAQ: PIRS).
Source Fool.com