There aren't many biotechs that are more exciting than Viking Therapeutics (VKTX -7.45%) right now. Thanks to its clinical-stage candidate for weight loss, there's a real chance that this competitor could see its shares soar for years.But that doesn't mean you should rush to buy the stock without understanding what else is going on with this stock and why it's making the changes it's making. Let's examine three things you'll need to factor into your decision if you plan on investing in Viking Therapeutics t ...