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” above. 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 by other countries in response to such actions or threatened actions by the United States, may adversely affect our business, operations, and financial results.

In late January 2025, the U.S. government commenced a broad review of U.S. trade relations and began issuing numerous executive orders and other public policy statements imposing, or threatening to impose, tariffs on certain countries, materials, and industries, including semiconductors. In response, impacted countries have imposed or threatened various corresponding retaliatory tariffs. We rely on a global sourcing strategy and third-party contract manufacturers in markets 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 and the imposition of tariffs, or retaliatory responses thereto, could adversely impact our business, operations, and financial results, including by increasing our costs and making our products less competitive. The tariff policy environment has been and can be expected to continue to be dynamic. Tariff developments that would impact our business include, but are not limited to:

•Mexico and Canada tariffs. The U.S. government imposed 25% tariffs on imports from Canada and Mexico in March 2025, and thereafter announced that tariffs relating to products eligible for import under the United States-Mexico-Canada Agreement would be paused until April 2025. 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. Canada and Mexico have also announced responsive tariffs on certain exports of U.S. goods to those countries.

•Steel and aluminum tariffs. In March 2025, the U.S. government imposed 25% tariffs on imported steel and aluminum, including certain derivative goods that include certain of our products.

•China tariffs. In February 2025, the U.S. government imposed an additional 10% tariff, which was further increased to 20% in March 2025, on all imports from China, including components of finished products. These tariffs followed and were in addition to earlier action imposing 15% tariffs on imports from China in recent years. While we do not rely on third party manufacturing in China for our products, our supply chain includes certain China-based suppliers. China has retaliated against trade restrictions by raising tariffs, and imposing new tariffs, on certain exports of U.S. goods to China. China has also introduced blocking measures to restrict the ability of domestic companies to comply with U.S. trade restrictions, recently restricted the export of certain metals and prohibited the export of certain rare minerals from China to the United States.

•Reciprocal tariffs. The U.S. government has announced its intent to impose, beginning in April 2025, wide-ranging reciprocal tariffs to address trade deficits and perceived inconsistent economic treatment of importation between the United States and its trading partners. In addition to third-party manufacturing in Mexico and Canada, we also rely on third-party manufacturing operations in Thailand for a significant portion of our revenue. The imposition of new tariffs on imports from countries from which we source product inputs, or specifically targeting key materials or inputs into our products, could lead to higher costs and supply chain disruption.

We may take steps to attempt to mitigate the impact of tariffs on our business, including by making changes to our supply chain practices, sources of supply, or manufacturing locations or by passing the cost of tariffs to customers who take shipment of impacted products in the United States. These changes could lead to additional costs or capital investment and supply chain delays or disruption. Within the current trade policy environment, 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. 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 generally, defer orders or delivery of existing orders, or elect to shift purchases to other vendors, each of which would adversely impact our financial results and competitive position with customers.