I think saying "Nintendo soars" is a bit hyperbolic though, clearly their stock looking at it over the past 2-5 years is not in good shape and yes the yen/dollar fluctuation is helping them, but look at the soaring Nikkei in comparison Nintendo's bump from the improving Japanese economy and the more favourable yen/dollar is rather modest actually.
If it wasn't for the yen/dollar improving for Japanese companies, Nintendo would probably be dropping even further, so at least there's that, but I'm not even sure if that's a great thing for Nintendo as it indicates more that the stock is only stabilizing a little bit due to outside factors, not because of company performance or policy shift.
In particular the pronunced overall drop in Nintendo's stock since last November's launch of Wii U is troubling. It shows that the investors are aware of the system and its problems, it's not something Nintendo has been able to quietly hide or deflect attention from. As such it probably means Nintendo stock will be getting hammered as long as the Wii U is not performing to par.
Which is why I wouldn't touch their stock with a 50 foot pole.
