Its ambitious business model may not be sustainable. Ginkgo Bioworks (DNA -1.81%) stock has had a rough 12 months, falling 88%, and undergoing a reverse stock split on Aug. 20 that left its shares down by around 18% in the aftermath. Depending on which view of the company you subscribe to, things could keep getting worse for shareholders over the next couple of years -- or they could get a lot better. Let's game out a few scenarios so that you can understand whether this stock is worth taking a chance on, o ...