Mario Gabelli acquired 273 Thousand NorthWestern Energy Group shares worth $15.4 Million. That's 0.16% of their equity portfolio (152nd largest holding). The first NorthWestern Energy Group trade was made in Q4 2005. Since then Mario Gabelli bought shares 22 more times and sold shares on 31 occasions. The stake costed the investor $7.06 Million, netting the investor a gain of 118% so far.