Mario Gabelli’s GAMCO Investors is one of the most prominent funds in the investment universe, which is why we consider that its activity should be followed closely, especially by piggy-backers who try to mimic the activity of notorious investors. GAMCO reported an impressive performance for the last year, showing a revenue worth $344.3 million, versus $397.6 million reported a year earlier. Moreover, its EPS surged by an impressive 60% on the year to $4.54 per share, while the total value of Assets Under Management reached a record $47 billion, as the fund states in a press release. However, what is…