Net Sales
Total net sales increased $136.2 million, or 22.1%, to $752.7 million for the quarter ended September 29, 2025, from $616.5 million for the quarter ended September 30, 2024. The primary driver of this increase was strong demand in our aerospace and defense, data center computing, and networking end markets, the latter two being driven by generative AI. In addition, our medical, industrial, and instrumentation end market was also stronger as inventories and demand have normalized in this end market.
Total net sales increased $340.2 million, or 19.0%, to $2,132.0 million for the three quarters ended September 29, 2025, from $1,791.8 million for the three quarters ended September 30, 2024. The primary drivers of the increase were as discussed in the paragraph above.
Gross Profit and Margin Rate
Gross profit increased $26.8 million to $156.7 million for the quarter ended September 29, 2025, from $129.9 million for the quarter ended September 30, 2024, primarily due to higher sales. Gross margin rate decreased slightly to 20.8% for the quarter ended September 29, 2025, from 21.1% for the quarter ended September 30, 2024. This decrease was primarily due to ramp‑up costs incurred in the third quarter of 2025 in connection with our fabrication plant in Penang, Malaysia as compared to the third quarter of 2024.
Gross profit increased $85.0 million to $435.8 million for the three quarters ended September 29, 2025, from $350.8 million for the three quarters ended September 30, 2024, primarily due to higher sales. Gross margin rate increased to 20.4% for the three quarters ended September 29, 2025, from 19.6% for the three quarters ended September 30, 2024. The increase was primarily due to improved operational execution, favorable product mix, and increased volume of PCB shipments as compared to the same period of 2024.
Operating Expenses
Operating expenses increased $5.9 million to $84.8 million for the quarter ended September 29, 2025, from $78.9 million for the quarter ended September 30, 2024, primarily due to higher incentive compensation expense, stock-based compensation, and outside services costs.
Operating expenses increased $8.1 million to $251.9 million for the three quarters ended September 29, 2025, from $243.8 million for the three quarters ended September 30, 2024, primarily due to the absence of gains on the sale of assets primarily related to the sale of two buildings vacated with the closure of our Anaheim and Santa Clara plants of $14.4 million that occurred in the three quarters ended September 30, 2024, partially offset by the write down of our Hong Kong building of $6.1 million that occurred in the three quarters ended September 30, 2024. In addition, increased stock-based compensation and incentive compensation expense contributed to the higher operating expenses, partially offset by a decrease in amortization of definite-lived intangibles.
Operating Income and Margin Rate
Operating income increased $20.9 million to $71.9 million for the quarter ended September 29, 2025, from $51.0 million for the quarter ended September 30, 2024. Operating margin rate increased to 9.6% for the quarter ended September 29, 2025, from 8.3% for the quarter ended September 30, 2024. The primary drivers of these increases are discussed above in the variance explanations for Gross Profit and Margin Rate and Operating Expenses.
Operating income increased $76.9 million to $183.9 million for the three quarters ended September 29, 2025, from $107.0 million for the three quarters ended September 30, 2024. Operating margin rate increased to 8.6% for the three quarters ended September 29, 2025, from 6.0% for the three quarters ended September 30, 2024. The primary drivers of these increases are discussed above in the variance explanations for Gross Profit and Margin Rate and Operating Expenses.
Total Other Expense, Net
Total other expense, net decreased $15.9 million to $10.1 million for the quarter ended September 29, 2025, from $25.9 million for the quarter ended September 30, 2024, primarily as a result of lower unrealized foreign exchange losses during the quarter ended September 29, 2025. We utilize the Chinese Renminbi (RMB) and Malaysian Ringgit (MYR) at our China and Malaysia facilities, respectively, for employee‑related and other costs of running our operations in foreign countries. There was an unrealized loss from foreign exchange of $0.5 million during the quarter ended September 29, 2025, compared to $16.2 million during the quarter ended September 30, 2024. This unrealized loss was related to the translation of our China and Malaysia balance sheets from their local currencies into the U.S. dollar functional currency, resulting from weakening RMB and MYR during the quarter ended September 29, 2025 as compared to the quarter ended September 30, 2024.
Total other expense, net decreased $1.8 million to $35.6 million for the three quarters ended September 29, 2025, from $37.4 million for the three quarters ended September 30, 2024, primarily as a result of lower unrealized foreign exchange losses during the three quarters ended September 29, 2025. There was an unrealized loss from foreign exchange of $8.5 million during the three quarters ended September 29, 2025, compared to $12.0 million during the three quarters ended September 30, 2024. This decrease was primarily due to the foreign currency impacts discussed in the paragraph above.