>>73752087/biz/ here. Cover's stock is grossly overvalued (currently around 30 p/e, they were about 40 a while ago), plus the Japanese stock market in general is going down. You surely also have the fact that some retards (most investors) can't tell the difference between Cover and Anycolor.
Now, the real question to ask would be: why isn't Anycolor going (as much) down? Well, it's because of a stock split they had a while ago, plus financial shenanigans. But once the next report comes out it will be a bloodbath.