Exhibit 99.1

News Release

PDF Solutions^® Reports First Fiscal Quarter Results

SANTA CLARA, Calif. — May 1, 2019 — PDF Solutions, Inc. (“PDF Solutions” or the “Company”) (NASDAQ: PDFS), a leading provider of differentiated data and analytics solutions to the semiconductor and electronics industries, today announced financial results for its first fiscal quarter ended March 31, 2019.

First Fiscal Quarter 2019 Financial Results

Total revenues for the first fiscal quarter of 2019 were $20.5 million, up 4% from $19.7 million for the fourth fiscal quarter of 2018 and down 17% from $24.7 million for the first fiscal quarter of 2018. Solutions revenue for the first fiscal quarter of 2019 was $16.7 million, up 32% from $12.7 million for the fourth fiscal quarter of 2018 and down 8% from $18.2 million for the first fiscal quarter of 2018. Gainshare performance incentives revenue for the first fiscal quarter of 2019 was $3.9 million, down 45% from $7.1 million for the fourth fiscal quarter of 2018 and down 41% from $6.5 million for the first fiscal quarter of 2018.

First quarter 2019 gross margin of 62% improved from 54% compared to the first fiscal quarter of 2018, reflecting the impact of the evolution of the Company’s business model to deliver its solutions via high margin, recurring software subscriptions.

On a GAAP basis, net loss for the first fiscal quarter of 2019 was $2.7 million, or ($0.08) per basic and diluted share, compared to net loss of $3.1 million, or ($0.10) per basic and diluted share, for the fourth fiscal quarter of 2018, and compared to net loss of $0.4 million, or ($0.01) per basic and diluted share, for the first fiscal quarter of 2018.

Non-GAAP net income for the first fiscal quarter of 2019 was $0.8 million, or $0.03 per diluted share, compared to net loss of $0.4 million, or ($0.01) per diluted share, for the fourth fiscal quarter of 2018, and compared to net income of $2.2 million, or $0.07 per diluted share, for the first fiscal quarter of 2018.

Cash and cash equivalents at March 31, 2019, were $90.4 million, compared to $96.1 million at December 31, 2018.

In connection with the Company’s previously announced stock repurchase program, the Company repurchased approximately 314,000 shares at an average price of $12.46 per share for a total of $3.9 million during the first fiscal quarter of 2019.

Operating Highlights

Conference Call

As previously announced, PDF Solutions will discuss these results on a live conference call beginning at 2:00 p.m. Pacific Time/5:00 p.m. Eastern Time today. The call will be simultaneously web cast on PDF Solutions’ website at http://ir.pdf.com/webcasts. A replay of the web cast will be available at the same website address beginning approximately two hours after completion of the live call. A copy of this press release, including the disclosure and reconciliation of certain non-GAAP financial measures to the comparable GAAP measures, which non-GAAP measures may be used periodically by PDF Solutions’ management when discussing financial results with investors and analysts, will also be available on PDF Solutions’ website at http://www.pdf.com/press-releases following the date of this release.

First Fiscal Quarter 2019 Financial Commentary Available Online

A Management Report reviewing the Company’s first fiscal year 2019 financial results will be furnished to the SEC on Form 8-K and published on the Company’s website at http://ir.pdf.com/financial-reports. Analysts and investors are encouraged to review this commentary prior to participating in the conference call webcast.

Information Regarding Use of Non-GAAP Financial Measures

In addition to providing results that are determined in accordance with Generally Accepted Accounting Principles in the United States of America (GAAP), PDF Solutions also provides certain non-GAAP financial measures. Non-GAAP net income (loss) excludes the effects of non-recurring items (including severance payments, restructuring charges, write-down in value of property and equipment, and adjustment to contingent consideration related to acquisition), stock-based compensation expense, amortization of acquired technology and other acquired intangible assets, and their related income tax effects, as applicable, as well as adjusts for the non-cash portion of income taxes. These non-GAAP financial measures are used by management internally to measure the Company’s profitability and performance. PDF Solutions’ management believes that these non-GAAP measures provide useful supplemental information to investors regarding the Company’s ongoing operations in light of the fact that none of these categories of expense has a current effect on the future uses of cash (with the exception of certain non-recurring items) nor do they impact the generation of current or future revenues. These non-GAAP results should not be considered an alternative to, or a substitute for, GAAP financial information, and may differ from similarly titled non-GAAP measures used by other companies. In particular, these non-GAAP financial measures are not a substitute for GAAP measures of income or loss as a measure of performance, or to cash flows from operating, investing and financing activities as a measure of liquidity. Since management uses these non-GAAP financial measures internally to measure profitability and performance, PDF Solutions has included these non-GAAP measures to give investors an opportunity to see the Company’s financial results as viewed by management. A reconciliation of the comparable GAAP financial measures to the non-GAAP financial measures is provided at the end of the Company’s financial statements presented below.   

Forward-Looking Statements

The statements made in this press release and on the planned conference call regarding the Company’s future expected business performance and financial results are forward looking and are subject to events and circumstances of the future. Actual results could differ materially from those expressed in these forward-looking statements. Risks and uncertainties that could cause results to differ materially include risks associated with: customers’ production volumes under contracts that provide Gainshare royalties, cost and schedule of new product development; continued adoption of the Company’s solutions by new and existing customers; project milestones or delays and performance criteria achieved; the provision of technology and services prior to the execution of a final contract; and other risks set forth in PDF Solutions’ periodic public filings with the Securities and Exchange Commission, including, without limitation, its Annual Reports on Form 10-K, most recently filed for the year ended December 31, 2018, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K and amendments to such reports. The forward-looking statements made in the conference call are made as of the date hereof, and PDF Solutions does not assume any obligation to update such statements nor the reasons why actual results could differ materially from those projected in such statements.

About PDF Solutions

PDF Solutions (NASDAQ: PDFS) offers an end-to-end analytics platform that empowers engineers and data scientists across the semiconductor ecosystem to rapidly improve the yield, quality, and profitability of their products. By combining industry-leading data analytics and professional services with exclusive, differentiated product data generated during the manufacturing process, PDF Solutions is delivering on the promise of Industry 4.0 today by transforming how the ecosystem collects, analyzes, and shares data. Key Fortune 500 organizations around the world rely on PDF Solutions to remove the data barriers that encumber and constrain new product introductions and to deliver the machine learning insights that drive efficient and profitable high-volume manufacturing.

Headquartered in Santa Clara, California, PDF Solutions also operates worldwide in Canada, China, France, Germany, Italy, Japan, Korea, and Taiwan. For the Company’s latest news and information, visit http://www.pdf.com/.

Exensio, PDF Solutions, and the PDF Solutions logo are registered trademarks of PDF Solutions, Inc. or its subsidiaries. DFI, Stream.AI, and StreamMosaic are trademarks of PDF Solutions, Inc.

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