Better Artificial Intelligence Stock: Aehr Test Systems vs. KLA Corporation

Robert Izquierdo, The Motley Fool

Sat, September 19, 2026 at 7:23 PM GMT+3 5 min read

Choosing between a niche equipment provider and a diversified industry titan requires balancing high growth potential against established stability. Here is how Aehr Test Systems (NASDAQ:AEHR) and KLA (NASDAQ:KLAC) compare for investors.

Aehr Test Systems focuses on specific stress-testing solutions for power semiconductors and memory, while KLA provides broad process control tools used across the entire chip-making industry. While they both operate in the same sector, their scale and risk profiles differ significantly, making them attractive to different types of portfolios.

The case for Aehr Test Systems

Aehr Test Systems designs and sells specialized equipment for the testing and stabilization of semiconductor products in various forms, including wafers and singulated dies. The company focuses on the high-growth silicon carbide market for electric vehicles and high-bandwidth memory for artificial intelligence infrastructure. In its 2026 fiscal year (FY), which ended May 29, its five largest customers accounted for nearly 70% of net sales, and customer concentration like this adds a layer of risk to the business.

In FY 2026, revenue reached $50.0 million, representing a decline of 15.2% compared to the previous year. This contraction followed a period of higher operating costs, resulting in a net loss of $7.1 million for the period. The net margin, which represents the percentage of revenue remaining as profit after all expenses, was -14.3% in the latest fiscal year.

As of its May 2026 balance sheet, the debt-to-equity ratio is zero, indicating that the company has no debt relative to its shareholder equity. The current ratio, which measures a company's ability to cover short-term liabilities with short-term assets, is 10.3x. Free cash flow, defined as cash from operations minus capital expenditures, was a negative $5.4 million for the fiscal year ended in May.

The case for KLA

KLA develops equipment and services for advanced process control, helping manufacturers identify defects during the chip-making process to improve production yields. Taiwan Semiconductor Manufacturing Company is a major customer, accounting for more than 10% of total revenues, and customer concentration like this adds a layer of risk to the business. Beyond equipment sales, the company maintains a steady services business that accounts for roughly 23% of its total revenue.

In FY 2026, ended June 30, revenue reached $13.6 billion, an increase of 11.7% over the prior year. This growth supported a net income $4.8 billion, showcasing the company's ability to scale operations profitably. The net margin for the fiscal year was 35.6%, suggesting that more than a third of every dollar earned in revenue was retained as profit.

As of its June 2026 balance sheet, the debt-to-equity ratio is 1.0x, showing an equal balance between total debt and shareholder equity. The current ratio is 2.9x, indicating the company maintains sufficient liquidity to meet its immediate financial obligations. Free cash flow reached $3.8 billion for the fiscal year ended in June.

Risk profile comparison

Aehr Test Systems faces extreme revenue concentration where a few customers dictate much of its financial health. The business is highly cyclical and sensitive to the capital expenditure cycles of electric vehicle and memory manufacturers. It is also exposed to geopolitical tensions involving the United States, China, and Taiwan, which can lead to supply chain disruptions or export restrictions. Furthermore, the company must compete with much larger manufacturers.

KLA deals with its own form of customer concentration, particularly its reliance on major manufacturers such as Taiwan Semiconductor Manufacturing Company. The company faces stiff competition from industry peers such as Applied Materials and Lasertec. Operations are also subject to stringent U.S. export controls that impact sales in China. Additionally, KLA must manage complex cybersecurity risks due to the sensitivity of its intellectual property and the global nature of its information technology infrastructure.

Valuation comparison

KLA trades at a more modest valuation relative to its earnings estimates, while Aehr Test Systems carries a much higher multiple despite its recent net loss.

Valuation metrics sourced from Financial Modeling Prep (FMP) and may differ from other data providers.

Which stock would I buy in 2026?

KLA Corporation and Aehr Test Systems are both critical players in the semiconductor equipment industry, but they cater to entirely different risk profiles and market caps for investors seeking exposure to the artificial intelligence sector. KLA is a mega-cap global market leader in process control and wafer inspection, while Aehr is a small-cap high-growth player specializing in wafer-level test and burn-in solutions.

Between the two, I would invest in KLA for several reasons. It is generating profits, pays a dividend, and its share price valuation is far more reasonable than Aehr. As an industry titan, KLA holds a strong competitive moat, since customers would incur high switching costs to move to a rival.

Aehr Test Systems is the smaller, up-and-coming company. However, it's not profitable, and while it ended its FY 2026 with fourth-quarter sales of $18.8 million, compared to $14.1 million in the prior year, and record bookings of $60.7 million, it isn't as financially strong as KLA, given its negative free cash flow. Moreover, Aehr's high stock valuation suggests its future growth has already been factored into the share price, limiting upside potential.

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Robert Izquierdo has positions in Taiwan Semiconductor Manufacturing. The Motley Fool has positions in and recommends Applied Materials, KLA, and Taiwan Semiconductor Manufacturing. The Motley Fool recommends Lasertec. The Motley Fool has a disclosure policy.

Better Artificial Intelligence Stock: Aehr Test Systems vs. KLA Corporation was originally published by The Motley Fool