That's not saying much; we have seen Nintendo's stock price getting much higher during the DS-Wii Era.
Having say that, well, the fact that one single app (that is not even developed by Nintendo despite having huge stake in it) managed to send Nintendo to what it is at right now is a miracle nonetheless. However, stock price is about speculation and expectation. To sustain such "high hope", Nintendo will have to deliver in its own mobile games to come (we are counting on you, Animal Crossing Mobile Fest!). If they failed to achieve comparable success or could not come out soon enough, that 75%-ish price gain can also perish in a matter of days.
2014 was a good small spike because it was such a amazing year for WiiU, like everyone was admitting that they wanted one that year, wanted one, but never actually bought one, atleast in as much as it was wanted
My face when a wave of investors realize that The Pokemon Company is a separate entity, and that Nintendo is basically just making licensing fees from Pokemon Go.