Sifting through countless of stocks in the Semiconductors & Semiconductor Equipment 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 PDF Solutions, Inc., ACM Research or Inc. 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 PDF Solutions, Inc., ACM Research and Inc. compare based on key financial metrics to determine which better meets your investment needs.

About PDF Solutions, Inc., ACM Research and Inc.

PDF Solutions, Inc. provides proprietary software, physical intellectual property for integrated circuit designs, electrical measurement hardware tools, proven methodologies, and professional services in the United States, Japan, China, and internationally. The company offers Exensio software, such as Manufacturing Analytics, which uses a proprietary database schema to store collected data; Process Control, which provides failure detection and classification capabilities for monitoring, alarming, and controlling manufacturing tool sets; Test Operations, which offer data collection and analysis capabilities; and Assembly Operations, which provide device manufacturers with the capability to link assembly and packaging data, including fabrication and characterization data across the product life cycle. It also provides Sapience Data Platform, which unifies fragmented data from diverse equipment and protocols across the factory floor; Sapience Manufacturing Hub enterprise, a connectivity platform between enterprise applications; DirectScan systems, such as Proprietary Software and eProbe Non-Contact E-Beam Tool; and Characterization Vehicle (CV) system, which includes CV Test Chips, pdFasTest Electrical Tester, and Exensio characterization software. In addition, the company offers Cimetrix software products that enable equipment manufacturers to provide standard interfaces on their products for equipment communication, control, and data collection; equipment factory connectivity products, such as Cimetrix CIMConnect, Cimetrix CIM300, and Cimetrix CIMPortal Plus; equipment factory connectivity testing and control products; secureWISE systems, including software, servers, and networks; software-as-a-service; software and hardware installation and configuration; system/data integration, and value realization; and technical support and maintenance for hardware and software. PDF Solutions, Inc. was founded in 1991 and is headquartered in Santa Clara, California.

ACM Research, Inc., together with its subsidiaries, develops, manufactures, and sells capital equipment in Mainland China and internationally. It also develops, manufactures, and sells a range of packaging tools to wafer assembly and packaging customers. The company provides wet cleaning equipment for front end production processes; electrochemical plating, furnace, PECVD, and track platforms; Space Alternated Phase Shift, technology for flat and wafer surfaces; timely energized bubble oscillation, technology for patterned wafer surfaces at advanced process nodes; and Tahoe technology; and semi-critical cleaning tools. It also offers advanced packaging equipment, such as coaters, developers, photoresist strippers, scrubbers, wet etchers and copper-plating equipment; and advanced packaging products include: Ultra ECP ap, which delivers a uniform metal layer to finished wafers prior to packaging; Ultra C Developer, which applies liquid developer to selected parts of photoresist to resolve an image; Ultra C PR Megasonic-Assisted Stripper, which removes photoresist; Ultra C Scrubber, which scrubs and cleans wafers; Ultra C Thin Wafer Scrubber, which addresses a sub-market of cleaning very thin wafers for certain Asian assembly factories; and Ultra C Wet Etcher, which etches silicon wafers and copper and titanium interconnects. In addition, the company provides ECP technology for advanced metal plating; Ultra fn Furnace, a dry processing tool; Ultra Pmax PECVD tools, a proprietary designed chamber, gas distribution unit, and chuck; and Ultra Track, a 300mm process tool that delivers uniform air downflow, fast robot handling and configurable software to address specific customer requirements. It markets and sells its products under the SAPS, TEBO, ULTRA C, ULTRA Fn, Ultra ECP, Ultra ECP map, and Ultra ECP ap trademarks through direct sales force and third-party representatives. ACM Research, Inc. was incorporated in 1998 and is headquartered in Fremont, California.

Latest Semiconductors & Semiconductor Equipment and PDF Solutions, Inc., ACM Research, Inc. Stock News

As of October 20, 2026, PDF Solutions, Inc. had a $1.7 billion market capitalization, compared to the Semiconductors & Semiconductor Equipment median of $4.0 million. PDF Solutions, Inc.’s stock is up 54.3% in 2026, up 3.8% in the previous five trading days and up 49.91% in the past year.

Currently, PDF Solutions, Inc.’s price-earnings ratio is 162.8. PDF Solutions, Inc.’s trailing 12-month revenue is $241.2 million with a 4.3% net profit margin. Year-over-year quarterly sales growth most recently was 19.0%. Analysts expect adjusted earnings to reach $1.294 per share for the current fiscal year. PDF Solutions, Inc. does not currently pay a dividend.

As of October 20, 2026, ACM Research, Inc. had a $3.8 billion market cap, putting it in the 64th percentile of all stocks. ACM Research, Inc.’s stock is up 38.6% in 2026, down 10.5% in the previous five trading days and up 44.37% in the past year.

Currently, ACM Research, Inc.’s price-earnings ratio is 25.7. ACM Research, Inc.’s trailing 12-month revenue is $1.0 billion with a 14.5% net profit margin. Year-over-year quarterly sales growth most recently was 36.0%. Analysts expect adjusted earnings to reach $2.139 per share for the current fiscal year. ACM Research, Inc. does not currently pay a dividend.

How We Compare PDF Solutions, Inc., ACM Research and Inc. 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 PDF Solutions, Inc., ACM Research and Inc.’s stock grades to see how they measure up against one another.

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PDF Solutions, Inc., ACM Research and Inc. Stock Value Grades

Company	Ticker	Value
PDF Solutions, Inc.	PDFS	F
ACM Research, Inc.	ACMR	D

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.

PDF Solutions, Inc. has a Value Score of 4, which is Ultra Expensive. ACM Research, Inc. has a Value Score of 22, which is Expensive.

The Value Stock Winner: No Clear Winner

Neither PDF Solutions, Inc., ACM Research or Inc. 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 PDF Solutions, Inc., ACM Research or Inc. is the better investment when it comes to value.

PDF Solutions, Inc., ACM Research and Inc.’s Quality Grades

Company	Ticker	Quality
PDF Solutions, Inc.	PDFS	B
ACM Research, Inc.	ACMR	D

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.

PDF Solutions, Inc. has a Quality Score of 69, which is Strong. ACM Research, Inc. has a Quality Score of 34, which is Weak.

The Quality Grade Winner: PDF Solutions, Inc.

As you can clearly see from the Quality Grade breakdown above, PDF Solutions, Inc. has a better overall quality grade than ACM Research, Inc.. For investors who are looking for companies with higher quality than others in the same industry, PDF Solutions, Inc. 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.

PDF Solutions, Inc., ACM Research and Inc.’s Momentum Grades

Company	Ticker	Momentum
PDF Solutions, Inc.	PDFS	B
ACM Research, Inc.	ACMR	B

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%.

PDF Solutions, Inc. has a Momentum Score of 67, which is Strong. ACM Research, Inc. has a Momentum Score of 65, which is Strong.

The Momentum Grade Winner: It’s a Tie!

Looking at the Momentum Grade breakdown above, both PDF Solutions, Inc., ACM Research and Inc. have a grade of B. 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 PDF Solutions, Inc., ACM Research and Inc. Grades

In addition to Value, Momentum and Quality, 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 PDF Solutions, Inc., ACM Research and Inc. pass any of our 60+ stock screens that have outperformed the market since their creation.

So, Which Is the Better Investment, PDF Solutions, Inc., ACM Research or Inc. Stock?

Overall, PDF Solutions, Inc. stock has a Value Score of 4, Momentum Score of 67 and Quality Score of 69.

ACM Research, Inc. stock has a Value Score of 22, Momentum Score of 65 and Quality Score of 34.

Comparing PDF Solutions, Inc., ACM Research and Inc.’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.