Nvidia (NVDA), Super Micro Computer (SMCI), and Dell (DELL) shares plunged Monday after Singapore said it’s investigating whether servers shipped to Malaysia containing chips barred from China ended up in the mainland.

Police in the city-state arrested several people for their alleged roles in procuring and shipping Nvidia chips in violation of American sanctions, Bloomberg reports. The U.S. has been investigating whether Chinese AI startup DeepSeek had circumvented curbs that way, it said earlier.

Singapore is seeking further information from Malaysia and the U.S. to determine the final destination of the Dell and Super Micro Computer servers, Law Minister K Shanmugam told reporters on Monday. The purchasers had misled suppliers about the ultimate destination of the equipment, he said.

The investigation risks increasing U.S. scrutiny of equipment exports by the American companies, a potential drag on sales growth. The news also comes amid investor caution ahead of the scheduled implementation of higher U.S. tariffs on goods from China, Mexico and Canada.

Nvidia stock was down about 6% in Monday afternoon trading. Super Micro Computer Stock fell 9%, and Dell slipped about 4.5%.

Intel (INTC) stock, by contrast, got a boost on Monday on a report that its faltering chip manufacturing business could get a boost from its rivals.

Nvidia and Broadcom (AVGO) are testing chip manufacturing with Intel on its most advanced 18A process for cutting-edge chips, such as those for AI, Reuters reports.

Intel stock was up about 1.5% on Monday afternoon. The U.S.-traded shares of top chip foundry Taiwan Semiconductor Manufacturing Corp. (TSM) (TSMC) fell 2.5%.

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