Mario Gabelli acquired 280 Thousand NorthWestern Energy Group shares worth $14.3 Million. That's 0.15% of their equity portfolio (161st 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 30 occasions. The stake costed the investor $7.22 Million, netting the investor a gain of 98% so far.