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 Aehr Test Systems, Inc., PDF Solutions 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 Aehr Test Systems, Inc., PDF Solutions and Inc. compare based on key financial metrics to determine which better meets your investment needs.

About Aehr Test Systems, Inc., PDF Solutions and Inc.

Aehr Test Systems, Inc. provides test solutions for testing, burning-in, and semiconductor devices in wafer level, singulated die, package part form, and installed systems in the United States, Asia, and Europe. Its product portfolio includes FOX-XP and FOX-NP systems that are full wafer contact and singulated die/module test and burn-in systems that test, burn-in, and stabilize range of devices, including silicon carbide-based and other power semiconductors, 2D, and 3D sensors used in mobile phones, tablets and other computing devices, memory semiconductors, processors, microcontrollers, systems-on-a-chip, and photonics and integrated optical devices. The company offers FOX-CP system, a low-cost single-wafer compact test solution for logic, memory, and photonic devices; and FOX WaferPak Contactor, a full wafer contactor capable of testing wafers up to 300mm that enables integrated circuit manufacturers to perform test, burn-in, and stabilization of full wafers on the FOX-P systems. In addition, it provides FOX DiePak Carrier, which allows testing, burning in, and stabilization of singulated bare die and modules; and FOX DiePak Loader. The company was incorporated in 1977 and is headquartered in Fremont, California.

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.

Latest Semiconductors & Semiconductor Equipment and Aehr Test Systems, Inc., PDF Solutions, Inc. Stock News

As of May 13, 2026, Aehr Test Systems, Inc. had a $3.2 billion market capitalization, compared to the Semiconductors & Semiconductor Equipment median of $5.0 million. Aehr Test Systems, Inc.’s stock is NA in 2026, NA in the previous five trading days and up 1033.37% in the past year.

Currently, Aehr Test Systems, Inc. does not have a price-earnings ratio. Aehr Test Systems, Inc.’s trailing 12-month revenue is $45.3 million with a -25.2% net profit margin. Year-over-year quarterly sales growth most recently was -43.7%. Analysts expect adjusted earnings to reach $-0.095 per share for the current fiscal year. Aehr Test Systems, Inc. does not currently pay a dividend.

Currently, PDF Solutions, Inc.’s price-earnings ratio is 284.9. PDF Solutions, Inc.’s trailing 12-month revenue is $231.4 million with a 3.1% net profit margin. Year-over-year quarterly sales growth most recently was 25.7%. Analysts expect adjusted earnings to reach $1.263 per share for the current fiscal year. PDF Solutions, Inc. does not currently pay a dividend.

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

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Aehr Test Systems, Inc., PDF Solutions and Inc. Growth Grades

Company	Ticker	Growth
Aehr Test Systems, Inc.	AEHR	F
PDF Solutions, Inc.	PDFS	B

The foundation of growth investing is seeking out stocks of companies exhibiting strong, consistent and prolonged growth that is expected to continue into the future.

In order to compute the growth score and assign it a letter grade, the percentile ranks for each of three components‐consistency of annual sales growth, five-year sales growth rankings adjusted for extreme levels, and consistency of positive annual cash from operations‐must be determined. These three rank figures are added together, and the sum is ranked against the entire stock universe to arrive at a company’s Growth Score to create an equal distribution of grades.

The companies in the bottom 20% of the stock universe receive Growth Grades of F, considered to be very weak, while those in the top 20% receive A grades, which are considered very strong.

Aehr Test Systems, Inc. has a Growth Score of 16, which is Very Weak. PDF Solutions, Inc. has a Growth Score of 69, which is Strong.

The Growth Grade Winner: PDF Solutions, Inc.

As you can clearly see from the Growth Grade breakdown above, PDF Solutions, Inc. has a more attractive growth grade than Aehr Test Systems, Inc.. For investors who focus solely on how a company is growing relative to other companies in the same industry, PDF Solutions, Inc. could be a good stock to add to their portfolio. However, it’s important for investors to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Aehr Test Systems, Inc., PDF Solutions and Inc.’s Momentum Grades

Company	Ticker	Momentum
Aehr Test Systems, Inc.	AEHR	A
PDF Solutions, Inc.	PDFS	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%.

Aehr Test Systems, Inc. has a Momentum Score of 100, which is Very Strong. PDF Solutions, Inc. has a Momentum Score of 93, which is Very Strong.

The Momentum Grade Winner: It’s a Tie!

Looking at the Momentum Grade breakdown above, both Aehr Test Systems, Inc., PDF Solutions and Inc. 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.

Aehr Test Systems, Inc., PDF Solutions and Inc.’s Estimate Revisions Grades

Company	Ticker	Earnings Estimate
Aehr Test Systems, Inc.	AEHR	B
PDF Solutions, Inc.	PDFS	A

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

Estimate revisions offer an indication of what analysts are thinking about the short-term prospects of a firm. Estimate revisions are based on the statistical significance of a firm’s last two quarterly earnings surprises and the percentage change in its consensus estimate for the current fiscal year over the past month and past three months.

Aehr Test Systems, Inc. has a Earnings Estimate Score of 63, which is Positive. PDF Solutions, Inc. has a Earnings Estimate Score of 84, which is Very Positive.

The Earnings Estimate Revisions Grade Winner: PDF Solutions, Inc.

As you can clearly see from the Earnings Estimate Revisions Grade breakdown above, PDF Solutions, Inc. has a better Earnings Estimate Revisions Grade than Aehr Test Systems, Inc.. For those who are specifically looking for companies with better short-term prospects when compared to other companies in the same industry, PDF Solutions, Inc. could be a good stock to invest in. However, it’s important to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Other Aehr Test Systems, Inc., PDF Solutions and Inc. Grades

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

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 Quality Grade comes from the ranking of key metrics. Specifically, the quality grade is the percentile rank of the composite 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 F-Score.

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 Aehr Test Systems, Inc., PDF Solutions and Inc. pass any of our 60+ stock screens that have outperformed the market since their creation.

So, Which Is the Better Investment, Aehr Test Systems, Inc., PDF Solutions or Inc. Stock?

Overall, Aehr Test Systems, Inc. stock has a Growth Score of 16, Momentum Score of 100 and Estimate Revisions Score of 63.

PDF Solutions, Inc. stock has a Growth Score of 69, Momentum Score of 93 and Estimate Revisions Score of 84.

Comparing Aehr Test Systems, Inc., PDF Solutions 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.