Billionaire Mario Gabelli’s 10 Small-Cap Stock Picks with Huge Upside Potential

4. Mueller Industries Inc. (NYSE:MLI)

GAMCO Investors’ Stake: $214.54 million

Number of Hedge Fund Holders: 34

Market Capitalization as of May 8: $8.38 billion

Average Upside Potential as of May 8: 38.39%

Mueller Industries Inc. (NYSE:MLI) manufactures and sells copper, brass, and aluminum products. It operates through three segments: Piping Systems, Industrial Metals, and Climate. It sells its products to wholesalers in the plumbing & refrigeration markets, distributors to the manufactured housing & recreational vehicle industries, building material retailers, and air-conditioning OEMs.

The Piping Systems Segment generated net sales of $639.7 million for Mueller in Q1 2025 due to higher selling prices, which were reflected in the increased raw material costs and tariffs. This outweighed modestly lower shipment volumes due to production challenges early in the quarter. The Piping Systems Segment also contributed significantly to the company’s profitability, reporting operating income of $158.2 million in Q1 2025, up from $142.7 million in Q1 2025.

Mueller Industries Inc. (NYSE:MLI) acknowledges the potential challenges posed by tariffs and trade policies, but it’s proactively implementing price adjustments where necessary to mitigate these effects. Despite some initial production disruptions, the Piping Systems Segment remains a focus for Mueller and uses the company’s established market presence to adjust pricing to maintain profitability.