CIENA CORP

Investing in our securities involves a high degree of risk. Before investing in our securities, you should consider carefully the information contained in this report and in our 2024 Annual Report, including the information under “Risk Factors” in Item 1A of Part I thereof. This report contains forward-looking statements that involve risks and uncertainties. See “Cautionary Note Regarding Forward-Looking Statements” in “Management’s Discussion and Analysis of Financial Conditions and Results of Operations” in Item 2 of Part I of this report. Our actual results could differ materially from those contained in the forward-looking statements. Any of the risks discussed in our 2024 Annual Report, in this report, in other reports we file with the SEC, and other risks we have not anticipated or discussed, could have a material adverse impact on our business, financial condition, or results of operations. Except as set forth below, there has been no material change to the material factors that make an investment in our securities speculative or risky from those presented in our 2024 Annual Report.

Tariffs and other import measures imposed by the United States or other countries may adversely affect our business, operations, and financial results.

In January 2025, the U.S. government commenced a broad review of U.S. trade relations and began imposing, or threatening to impose, tariffs on certain countries, materials, and industries. In response, certain impacted countries have imposed or threatened various retaliatory tariffs or other trade restrictions. We rely on a global sourcing strategy and third-party contract manufacturers outside of the United States to perform substantially all of our manufacturing. Moreover, revenue in the United States represented approximately 70% of our revenue in fiscal 2024. Significant changes to trade policy, the imposition of tariffs, or retaliatory responses thereto, have adversely impacted and could materially adversely impact our business, operations, and financial results, including by increasing our costs, by decreasing our profit margins, and/or by making our products less competitive. The tariff policy environment has been and can be expected to continue to be dynamic. Tariffs recently implemented or proposed that have impacted or could materially impact our business include tariffs on imports:

•from Canada and Mexico, as products making up a significant portion of our revenue are manufactured in or distributed from Mexico, and we generally introduce new products and conduct related early volume manufacturing in Canada;

•of steel and aluminum, including derivative goods that include certain of our products;

•from China, as our supply chain includes certain China-based suppliers; and

•from a wide range of countries globally, including Thailand, where we also rely on third-party manufacturing operations for a significant portion of our revenue.

The U.S. government is also currently investigating imports of a range of different products, including semiconductors, critical raw minerals, and derivative products relevant to our business and products, which could result in additional tariffs. Certain tariffs that have been implemented or proposed are subject to legal challenges, but there can be no assurance that such challenges will be successful or that, if successful, additional or alternative tariffs will not be imposed.

We have taken steps, and may take additional steps, to attempt to mitigate the impact of tariffs on our business, including: by availing ourselves of certain exemptions to tariffs; by making changes to our supply chain practices, sources of supply, or manufacturing locations; and by passing the cost of tariffs to customers. These changes could take considerable time to implement, result in significant costs, and cause supply chain delays or disruption. There can be no guarantee as to which of our products will be impacted by tariffs or eligible for exceptions under existing or future trade agreements or executive orders. Moreover, there can be no assurance as to customer reaction to the current trade environment, the imposition of new tariffs, or any tariff mitigation steps we elect to take. Among other things, customers may elect to reduce spending, renegotiate contracts, defer orders or delivery of existing orders, or shift purchases to other vendors, each of which would adversely impact our financial results and competitive position with customers.