What Lumentum Holdings Inc. told the SEC could break it.

China's recent export controls have already affected the availability and price of rare earth metals and other critical minerals for Lumentum and its supply chain and customers, hurting operations, margins and sales.

“For example, China's recent export controls affected the availability and price of rare earth metals and other critical minerals for us as well as our supply chain and customers, adversely affecting our operations, margins and sales.”

A few (anonymized) customers each exceed 10% of net revenue — Customer A at 16.0% and Customer B at 15.4% in FY2025 — and two customers were 13% and 11% of gross accounts receivable.

“During our fiscal years 2025, 2024 and 2023, net revenue generated from a single customer which represented 10% or greater of total net revenue is summarized as follows: Years Ended June 28, 2025 June 29, 2024 July 1, 2023 Customer A 16.0 % 11.4 % 15.3 % Customer B 15.4 % 18.9 % * Customer C * * 12.1 % Customer D * * 10.5 %”

2025 U.S. tariffs hit nearly all countries (15% to stacked >100% in some cases, heaviest on China), plus export controls/sanctions limiting China sales and pending Section 232 semiconductor investigations that could add tariffs.

“Throughout 2025, the U.S. imposed a series of tariffs on imported goods. While these tariffs are positioned to have the most significant impacts on goods originating from China, nearly all countries worldwide are impacted at levels ranging from 15% to stacked tariffs in excess of 100% in some cases. The tariff landscape continues to evolve daily and, as a result, the full impact of these tariff measures on our business is uncertain. In addition to the geographic tariffs, U.S. government investigations are currently underway that may result in new tariffs on certain products, including semiconductors, computers, and other products derivative of critical minerals.”

Lumentum buys raw materials, packages and components from a limited number of often small/specialized suppliers — some sole sources for certain materials/equipment/components — with no supply guarantees and frequently infeasible alternatives.

“We purchase raw materials, packages and components from a limited number of suppliers, who are often small and specialized. Additionally, some of our suppliers are our sole sources for certain materials, equipment and components. We depend on the timely and continued supply and quality of the materials, packages and components that our suppliers supply to us.”

Significant manufacturing is in the US, Thailand, China, the UK, Slovenia and Japan, with major contract manufacturers in Thailand, Taiwan, Malaysia and the Philippines; ~81% of revenue is from outside the US, concentrating tariff and regional risk.

“Our significant manufacturing facilities are located in the United States, Thailand, China, the United Kingdom, Slovenia, and Japan. ... Our significant contract manufacturing partners are located primarily in Thailand, Taiwan, Malaysia and the Philippines.”