If you want a good example of how volatile biotechnology stocks can be, look no further than Puma Biotechnology Inc. This cancer-focused biotechnology company was founded 8 years ago and went public in 2012 with shares trading around $10 per share. In 2014 that share price rocketed to +$260 following positive clinical trials for the breast cancer drug Nerlynx, which contributed towards the company’s valuation at $10 billion. Following this, mixed research results and delays in approval processes have caused the company share price to swing wildly with the stock price plummeting almost 80% this year. Shares plunged a further 48% on Friday 2nd November after the company reported disappointing sales of $52.6 million for Nerlynx, below expectations of $58.1 million. Furthermore, Puma Biotech indicated that the percentage of patients who discontinued the use of Nerlynx as a result of adverse events had increased to about 18%, which only added to the sell-off. The good news for shareholders is that this massive sell-off is probably overdone. Nerylnx’s sales are likely to increase as the drug becomes more globally used, which may indicate that this stock is currently at a bargain price.