Sifting through countless of stocks in the Metals & Mining industry can be tedious, and sometimes two stocks are just too similar to judge which is the better investment. If you’re on the fence about investing in Ero Copper Corp. or MP Materials Corp. because you’re not sure how they measure up, it’s important to compare them on a few factors before making your decision.

Read on to learn how Ero Copper Corp. and MP Materials Corp. compare based on key financial metrics to determine which better meets your investment needs.

About Ero Copper Corp. and MP Materials Corp.

Ero Copper Corp. engages in the exploration, development, and production of mining projects in Brazil. Its flagship asset includes Caraíba operations that comprise the production and sale of copper concentrates located in northeastern Bahia State, Brazil, as well as gold and silver produced and sold as by-products. The company was incorporated in 2016 and is headquartered in Vancouver, Canada.

MP Materials Corp., together with its subsidiaries, produces rare earth materials in the Western Hemisphere. The company operates in two segments, Materials and Magnetics. The Materials segment owns and operates the Mountain Pass Rare Earth Mine and Processing facility located near Mountain Pass, San Bernardino County, California. The Magnetics segment produces magnetic precursor products. The company was founded in 2017 and is headquartered in Las Vegas, Nevada.

Latest Metals & Mining and Ero Copper Corp., MP Materials Corp. Stock News

As of November 21, 2025, Ero Copper Corp. had a $2.2 billion market capitalization, compared to the Metals & Mining median of $1.6 million. Ero Copper Corp.’s stock is up 67.3% in 2025, up 4.9% in the previous five trading days and up 34.08% in the past year.

Currently, Ero Copper Corp.’s price-earnings ratio is 16.2. Ero Copper Corp.’s trailing 12-month revenue is $588.2 million with a 23.4% net profit margin. Year-over-year quarterly sales growth most recently was 41.9%. Analysts expect adjusted earnings to reach $2.089 per share for the current fiscal year. Ero Copper Corp. does not currently pay a dividend.

As of November 21, 2025, MP Materials Corp. had a $9.8 billion market cap, putting it in the 79th percentile of all stocks. MP Materials Corp.’s stock is up 276.7% in 2025, up 3.1% in the previous five trading days and up 206.72% in the past year.

Currently, MP Materials Corp. does not have a price-earnings ratio. MP Materials Corp.’s trailing 12-month revenue is $232.7 million with a -50.5% net profit margin. Year-over-year quarterly sales growth most recently was -14.8%. Analysts expect adjusted earnings to reach $-0.273 per share for the current fiscal year. MP Materials Corp. does not currently pay a dividend.

How We Compare Ero Copper Corp. and MP Materials Corp. Stock Grades

Stock evaluation requires access to huge amounts of data and the knowledge and time to sift through it all, make sense of financial ratios, read income statements and analyze recent stock movements. AAII created A+ Investor, a robust data suite that condenses data research in an actionable and customizable way suitable for investors of all knowledge levels, to help investors streamline and work through such data.

AAII’s proprietary stock grades come with A+ Investor. These offer intuitive A‐F grades for each of five key investing factors: value, growth, momentum, earnings estimate revisions and quality. Here, we’ll take a closer look at Ero Copper Corp. and MP Materials Corp.’s stock grades to see how they measure up against one another.

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Ero Copper Corp. and MP Materials Corp. Stock Value Grades

Company	Ticker	Value
Ero Copper Corp.	ERO	D
MP Materials Corp.	MP	F

Successful stock investing involves buying low and selling high, so stock valuation is an important consideration for stock selection.

Buying stocks that are going to go up typically means buying stocks that are undervalued in the first place, although momentum investors may argue that point.

AAII’s A+ Investor Value Grade derives from a stock’s value score. The Value Score is the percentile rank of the average of the percentile ranks of the price-to-sales ratio, price-earnings ratio, enterprise-value-to-EBITDA (EV/EBITDA) ratio, shareholder yield, price-to-book-value ratio and price-to-free-cash-flow ratio. The score is variable, meaning it can consider all six ratios or, should any of the six ratios not be valid, the remaining ratios that are valid. To be assigned a Value Score, stocks must have a valid (non-null) ratio and corresponding ranking for at least two of the six valuation ratios.

Stocks with a Value Score from 81 to 100 are considered deep value, those with a score between 61 and 80 are a good value and so on.

Ero Copper Corp. has a Value Score of 28, which is Expensive. MP Materials Corp. has a Value Score of 6, which is Ultra Expensive.

The Value Stock Winner: No Clear Winner

Neither Ero Copper Corp. or MP Materials Corp. has a high enough value grade to be considered a “winner.” Investors who are considering these companies should do additional due diligence and research to see if either could be a good addition to their portfolio. It’s important to look at a wide range of financial metrics in order to determine if Ero Copper Corp. or MP Materials Corp. is the better investment when it comes to value.

Ero Copper Corp. and MP Materials Corp.’s Quality Grades

Company	Ticker	Quality
Ero Copper Corp.	ERO	B
MP Materials Corp.	MP	F

Like the Value Grade, AAII’s A+ Investor Quality Grade comes from the percentile rank of key metrics. Specifically, the Quality Score is the percentile rank of the average of the percentile ranks of return on assets (ROA), return on invested capital (ROIC), gross profit relative to assets, buyback yield, change in total liabilities to assets, accruals, Z double prime bankruptcy risk (Z) score and the F-Score.

The score is variable, meaning it can consider all eight measures or, should any of the eight measures not be valid, the remaining measures that are valid. To be assigned a Quality Score, stocks must have a valid (non-null) measure and corresponding ranking for at least four of the eight quality measures.

The Quality Score is used to assess the underlying “quality” of a particular stock. A higher-quality stock possesses traits associated with upside potential and reduced downside risk. Backtesting of the Quality Grade shows that stocks with higher grades, on average, outperformed stocks with lower grades over the period of 1998 through 2019.

Stocks receive better grades (higher scores) for having higher scores for the quality subcomponents and worse grades (lower scores) for lower scores for the subcomponents.

Ero Copper Corp. has a Quality Score of 71, which is Strong. MP Materials Corp. has a Quality Score of 15, which is Very Weak.

The Quality Grade Winner: Ero Copper Corp.

As you can clearly see from the Quality Grade breakdown above, Ero Copper Corp. has a better overall quality grade than MP Materials Corp.. For investors who are looking for companies with higher quality than others in the same industry, Ero Copper Corp. could be a good stock to add to their portfolios. However, it’s important for investors to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Ero Copper Corp. and MP Materials Corp.’s Momentum Grades

Company	Ticker	Momentum
Ero Copper Corp.	ERO	A
MP Materials Corp.	MP	A

Momentum grades help to uncover stocks experiencing anomalously high rates of return; research finds that stocks with high relative levels of momentum tend to outperform, whereas those with low levels of momentum tend to continue underperforming. Momentum is based on the price change of a stock over a specified period relative to all other stocks.

Typically, AAII looks at the weighted relative strength over the trailing four quarters. The weighted four-quarter relative strength rank is the relative price change for each of the past four quarters. The most recent quarterly price change is given a weight of 40% and each of the three previous quarters are given a weighting of 20%.

Ero Copper Corp. has a Momentum Score of 88, which is Very Strong. MP Materials Corp. has a Momentum Score of 97, which is Very Strong.

The Momentum Grade Winner: It’s a Tie!

Looking at the Momentum Grade breakdown above, both Ero Copper Corp. and MP Materials Corp. have a grade of A. For those who focus solely on a company’s momentum, further research will need to be conducted into both companies to see if they fit your individual needs as an investor.

Other Ero Copper Corp. and MP Materials Corp. Grades

In addition to Value, Quality and Momentum, A+ Investor also provides grades for Growth and Estimate Revisions.

Earnings estimate revisions scores take into account the magnitude of a company’s earnings surprise in its last two reported fiscal quarters. Often, surprises beget further surprises‐or at least continued sales growth (the exact opposite is generally true, too).

Growth investing builds on the idea that stocks of companies exhibiting strong, consistent and prolonged growth outperform those of slower-growth companies. AAII measures growth through consistency of annual sales growth, five-year sales growth rankings adjusted for extreme levels, and consistency of positive annual cash from operations.

These 2 key factors, when combined with the above, provide a holistic view into a particular stock. Further, by joining A+ Investor you can see whether Ero Copper Corp. and MP Materials Corp. pass any of our 60+ stock screens that have outperformed the market since their creation.

So, Which Is the Better Investment, Ero Copper Corp. or MP Materials Corp. Stock?

Overall, Ero Copper Corp. stock has a Value Score of 28, Momentum Score of 88 and Quality Score of 71.

MP Materials Corp. stock has a Value Score of 6, Momentum Score of 97 and Quality Score of 15.

Comparing Ero Copper Corp. and MP Materials Corp.’s grades, scores and metrics can act as a solid basis to determine whether they may be a good investment or not. You’ll also want to look at your portfolio’s asset allocation as well as your risk tolerance and financial goals to see if either of these stocks would make a good fit for you. AAII can help you figure out which investments align with your individual needs and preferences.

Investors are encouraged to do their own due diligence and research. In this way, individuals can effectively become managers of their own assets‐without having to rely on others for financial independence. You can count on AAII for timeless articles on financial planning and stock-picking, unbiased research and actionable analysis.

A+ Investor adds to our qualitative teaching with a powerful data suite to help you whittle down investment choices to find stocks, exchange-traded funds (ETFs) or mutual funds that meet your needs.

AAII Disclaimer

We make no representations or warranties that any investor will, or is likely to, achieve profits similar to those shown, because past, hypothetical or simulated performance is not necessarily indicative of future results. Before making an investment decision, you should consider your circumstances and whether the information on our content is applicable to your situation. This information was prepared in good faith, and we accept no liability for any errors or omissions. The full disclaimer can be read here.