Mario Gabelli is one of the best-known value investors on Wall Street and is the founder of the asset management firm GAMCO Investors Inc. (formerly known as Gabelli Asset Management Company), which he launched in 1977. Gabelli, Chairman and CEO of GAMCO, built his reputation through deep fundamental research and a value approach, which is simple: identify a company’s private market value (PMV) and the catalysts that could unlock it.

According to the latest SEC filings for February 2026, GAMCO Investors’ 13F portfolio has nearly $10.5 billion across more than 1,000 securities, with the top 10 holdings accounting for close to 16% of those investments. However, the overall assets under management (AUM) across asset classes totaled $34.9 billion as of December 2025, up 10% from Q4 2024.

READ ALSO: 40 Most Popular Stocks Among Hedge Funds Heading Into 2026 and 11 Best Machine Learning Stocks to Buy According to Analysts.

Our review of his interviews and commentary suggests that Mario Gabelli is not just a longtime stock picker but also a close observer of industry shifts, capital markets, and corporate deal activity. He actively shares his insights on markets across various platforms. In a Bloomberg interview published on March 5, 2026, he argued that after losing the Warner Bros. battle, Netflix should be “knocking on Sony’s door” to tap Sony’s anime portfolio. As evidence of his eye for value-creation opportunities, GAMCO owns nearly 6 million shares of Warner Bros., according to a Bloomberg report, and also holds shares in Netflix and Paramount Skydance Corp., the winning bidder for Warner Bros.

With that, Gabelli is advising clients to reassess media holdings as M&A picks up. He described the M&A backdrop as “a terrific time,” pointing to better financing conditions, spinoffs, and financial engineering.

With that backdrop, let’s explore the 12 best stocks to buy according to Billionaire Mario Gabelli.

Our Methodology

To compile the list of Billionaire Mario Gabelli’s best stock picks, we reviewed the Q4 2025 13F portfolio of GAMCO Investors from Insider Monkey’s database. We then shortlisted and ranked the top 10 equity holdings by portfolio weight in ascending order.

Why are we interested in the stocks that hedge funds pile into? The reason is simple: our research has shown that we can outperform the market by imitating the top stock picks of the best hedge funds. Our quarterly newsletter’s strategy selects 14 small-cap and large-cap stocks every quarter and has returned 427.7% since May 2014, beating its benchmark by 264 percentage points (see more details here).

Note: All pricing data is as of market close on March 9, 2026.

12. National Fuel Gas Company (NYSE:NFG)

Position Weight / Position Value: 1.1% / $115.7 Million

National Fuel Gas Company (NYSE:NFG) is one of Mario Gabelli’s strongest investment ideas in the utilities sector. According to the 13F filings available in the Insider Monkey database, GAMCO Investors has held a position in the stock since at least Q3 2012, when it held around 3.84 million shares, valued at $207.4 million. While the hedge fund has reduced its position over the years, as of the end of Q4 2025, National Fuel Gas still accounts for 1.11% of the portfolio, with 1.45 million shares, up slightly from Q3’s 1.41 million shares.

National Fuel Gas Company’s (NYSE:NFG) stock has performed strongly with a solid 16% return in 2026 so far, after already appreciating 32% in 2025.

In Gabelli’s Q4 2025 Shareholder Commentary published in January 2026, Mario Gabelli said, “There are two reasons” to like the stock. First, he pointed to National Fuel Gas Company’s (NYSE:NFG) roughly 1.2 million acres in the Appalachian Basin and argued that “the value of gas reserves strategically located near population centers is unappreciated.” He highlighted two important factors—33% of U.S. gas comes from Appalachia, and natural gas provides 40% of the U.S.’s electric power, which justified his point. In a mid-2025 CNBC interview, Gabelli called these assets “fundamental to the U.S.”

Second, Gabelli said that the company’s “private market value” is “50% higher than the current price.” He believes the stock could command a much higher valuation if the market correctly factors in its value drivers. He argued,

NFG can use increasing levels of free cash flow to invest in the regulated utility business or split up the company. NFG is expected to earn around $7 a share in this fiscal year. It could earn $9 a share the following year. We put the company’s private market value at 50% higher than the current price. If analysts who follow utility stocks put a 16 multiple on NFG’s pro forma utility earnings, the stock will trade even higher.

The commentary also mentions that:

NFG’s pending $2.6 billion acquisition of CenterPoint Energy’s Ohio gas utility will roughly double NFG’s regulated utility rate base, expand its customer footprint, and increase the percentage of earnings derived from regulated operations.

All in all, National Fuel Gas Company (NYSE:NFG) appears to be a robust asset-value play, and Gabelli remains confident in the stock, as evidenced by the modest increase in the fund’s position as per the 13F filings. In the commentary, Gabelli also highlighted the 2.14% annual dividend yield, which supports long-term investors.

At the institutional level, Gabelli Funds LLC (2.48%) and GAMCO Investors (1.52%) hold approximately 4.0% stake in the company, making them the fourth-largest shareholders. Vanguard Group (12.81%) and BlackRock (9.29%) are the largest shareholders, according to Yahoo Finance data.

National Fuel Gas Company (NYSE:NFG) is a diversified U.S. energy company engaged in the production, gathering, transportation, storage, and distribution of natural gas.

11. Watts Water Technologies Inc. (NYSE:WTS)

Position Weight / Position Value: 1.1% / $117.5 Million

Watts Water Technologies Inc. (NYSE:WTS) is the 11th-largest holding for GAMCO Investors, and the fund’s 13F filings as of the end of Q4 2025 indicate it has reduced its position in the stock by around 3.5% versus last quarter, to 425,854 shares. That pales in comparison to the nearly 1 million shares it used to command in early 2020 and over 2 million in 2012, according to Insider Monkey’s database.

While the stake has gradually come down, the stock has performed strongly, rising 160% over the last 5 years, 36% in 2025, and 12% so far this year.

In mid-2025, Gabelli Funds had highlighted Watts Water Technologies Inc. (NYSE:WTS) as a strong player in the building-efficiency theme, along with Johnson Controls.

On a separate note, WTS’s CEO and President Robert J. Pagano Jr. sold 16,066 shares on Feb. 19, 2026, at prices of around $325-$330 per share, leading to total proceeds of roughly $5.26 million. While the sale reduced his stake by 7.8%, it appears to be a minor insider sale, as he still owns 191,202 shares of the company, as per the SEC filings.

On the market sentiment side, recent analyst commentary has been highly encouraging, especially following the company’s strong Q4 results. As per a February 13 report, Goldman Sachs raised the stock’s price target from $267 to $323 while maintaining a Neutral rating. Apart from the strong results, the firm noted that the company also provided a robust outlook for Q1 and FY26, supported by acquisitions, data center expansion, and continued repair/replacement demand.

On the same day, the analysts at Baird also raised the stock’s price target to $361 from $312 and maintained a Neutral rating despite a bright outlook.

Watts Water Technologies Inc. (NYSE:WTS) provides water technologies and solutions designed to promote safety, energy efficiency, and water conservation in commercial and residential buildings.