The US wants Chinese optics out of its AI data centres. Amazon and Microsoft pay first.

China’s two biggest optical module makers took a beating on Wednesday. Zhongji Innolight fell as much as 16%, according to the South China Morning Post. Bloomberg put the intraday drop at 14%. Eoptolink Technology slid with it.

The trigger was a Reuters report that the FCC intends to halt imports of new models of optical transceiver. The stated aim is to stop Chinese firms stealing data or planting malware inside American facilities. It narrows a broader draft ban on Chinese data centre devices onto one specific component.

That component is not exotic. Optical transceivers sit at either end of a fibre link and translate electrical signals into light and back again. Every rack in a modern AI cluster depends on them.

A rule aimed at China that lands on American buyers

Research firm Counterpoint published a note on Wednesday warning that the ban would damage the companies it is meant to protect. Hyperscalers such as Amazon and Microsoft would face higher costs if Chinese optics suppliers were cut off, analyst Neil Shah wrote. Their expensive AI accelerators would also run at lower utilisation.

“The belief that the optical transceiver market can be neatly divided geographically misinterprets how the hardware ecosystem operates,” Shah said in the note, reported by Bloomberg. “The global AI ecosystem remains heavily reliant on Chinese optical module vendors for scale execution.”

The dependency is not marginal. Counterpoint puts the Chinese share of global optical transceiver supply at nearly two thirds. Data from LightCounting, cited by Caixin, has Chinese companies holding seven of the top ten positions in optical modules worldwide.

Narrow it to the fastest parts and the concentration gets worse. Innolight and Eoptolink together account for more than 60% of the global market in 800G and above, according to the same LightCounting figures. Those are the modules AI clusters actually buy.

The Western suppliers inside the Chinese modules

Shah made a second point that complicates the security case. The transceivers Chinese firms build are not purely Chinese. They integrate chips from Broadcom and Marvell, plus lasers and optical chips from Lumentum and Japan’s Mitsubishi Electric.

Cut off the finished modules and those suppliers lose a customer. Markets did not read it that way on the day. Applied Optoelectronics, Coherent, and Nokia all rallied, and Caixin reported gains of 8% to 10% for Coherent, Lumentum, and Marvell.

So Lumentum and Marvell rose on a rule that removes one of their larger buyers. Whether that holds depends on how fast Western manufacturers can take the volume. Shah’s answer was blunt: they cannot, not within the next year or two.

“While policy initiatives seek to insulate critical AI supply chains, sudden regulatory shifts risk creating hardware bottlenecks that could slow down deployment schedules for the world’s largest cloud operators,” he said.

How exposed the Chinese firms actually are

The pain is genuinely mutual. Innolight booked 61.7% of its first-quarter 2026 revenue in the US, roughly 12bn yuan, per Caixin. Reuters reported the figure as 62%. Eoptolink earns 96% of its revenue from exports.

Both firms listed in Hong Kong only recently. Innolight raised money in an $8bn Hong Kong offering. Eoptolink followed with a $5bn listing, built on the same AI optical demand now under threat.

There is a counter-reading. A separate Bloomberg analysis argued that the ban would strain a fragile trade truce, but is unlikely to dent China’s export engine overall. Optics is one product line in a very large machine.

Beijing answered the same day

China’s Ministry of Commerce announced a set of countermeasures on Wednesday. Exports of drones, their key components, and related technologies to the US now face case-by-case scrutiny, effective immediately, the Associated Press reported.

The ministry added six US entities to a countermeasures list. They include Applied DNA Sciences and the non-governmental group Human Rights in China. It also barred a firm called Compliance Testing LLC from doing business in China, specifically for working with the FCC.

The ministry also opened a national security review of imported printing software and office equipment. Separately, US companies can no longer run follow-up factory inspections for Chinese CCC safety certification, which pushes that work to auditors outside the US.

Beijing framed the moves as a response to recent American restrictions. Those include an FCC drone import ban and the addition of 43 Chinese companies to a forced-labour entity list. Last week the FCC also put foreign-made humanoid robots and power inverters on its covered list, which had already drawn a retaliatory response involving rare earths.

All of this lands ahead of an expected visit by Xi Jinping to the US in September.

The transceiver rule is still a draft, and the FCC has softened one before. Its December ban on Chinese drone imports was later revised to let some models through. Nobody has yet explained who absorbs the gap in the meantime. On a buildout this size, a few months of delayed capacity costs far more than the components ever did.