The problem is that the price of stocks has fallen for a reason. Let's take Nissan as an example. They've actually lost suppliers of components who were based in the likes of Sendai so cannot manufacture their products. So they will have to find another source which may result in a reduced profit margin due to components being more expensive elsewhere... assuming these components were not only produced in Sendai due to exact specifications. If they have a replacement, the supplier can charge more knowing that one or more of their rivals have been wiped out. It's things like this that need to be considered before investing.