One of the things to keep in mind with bitcoin is that there is a downward movement almost every weekend, like clockwork. There's a thread about it here. There are a number of theories about why this happens. Some people think its due to people being unable to fund their exchange accounts on weekends, others that it is just a self-fulfilling prophecy. Or maybe it is something else entirely. The point is, I wouldn't worry too much about the current selloff.