Mueller Industries Inc. (NYSE:MLI) is one of the best stocks to buy according to billionaire Mario Gabelli. Mueller Industries Inc. (NYSE:MLI) is the largest holding in GAMCO Investors’ 13F portfolio, accounting for approximately 2.06% of total holdings. That said, it is also the stock that saw the biggest change in Q4 2025 among the 12 largest holdings. GAMCO reduced the position by around 15% to 1.87 million shares, down from 2.19 million in Q3 2025. GAMCO Investors started building a position around the ...