Hong Kong’s exports just logged their second-best month on record, yet its airport shipped fewer export tonnes than a year ago. The growth is in cargo passing through, which is exactly the kind of traffic US export-control enforcers have started to pull apart.

On 24 September, Hong Kong’s Census and Statistics Department reported that August exports rose 53% year on year to HK$667.9bn, second only to July’s record of HK$672.5bn, with a government spokesman crediting “robust demand for AI-related electronic products.” The same month at Hong Kong International Airport looked very different: total cargo slipped 1.2% to 422,000 tonnes, exports fell 8.8%, imports rose 3.6% and transshipment jumped 18.2%, according to Airport Authority Hong Kong’s 17 September release. Near-record value. Falling export tonnes. The gap between those two numbers says a lot about the kind of hub Hong Kong is turning into.

Value up, tonnes down

Part of the divergence is arithmetic. Hong Kong’s trade statistics count value across every mode, including trucks crossing into Guangdong, while the airport counts weight. And the tonnes that disappeared were largely light, cheap parcels. The EU ended its €150 de minimis exemption and introduced a €3 duty on low-value parcels on 1 July, and WorldACD data showed Hong Kong-Europe air tonnage dropping 12% in a single week in early July. The Airport Authority said Southeast Asia and the Chinese mainland helped cushion “softer traffic with Europe and the Middle East amid evolving regional trade dynamics.”

The cargo filling that space is heavy in dollars rather than kilos. Hong Kong handled more than half of China’s $239bn in chip imports in the first five months of this year, a record share compared with about a third a decade ago, according to a Bloomberg review of official data published on 2 July. The same report cited Hong Kong Trade Development Council research showing AI-related electronics now make up 57% of the city’s exports, up from 44% in 2024. “Hong Kong’s strong air cargo network and free-port status have made it a perfect trading hub for semiconductors, which are high-value, low-weight and time-sensitive,” Natixis economist Gary Ng told Bloomberg.

Cathay Cargo is riding the same wave. It carried 151,904 tonnes in August, up 8.6% year on year, but its revenue freight tonne-km rose only 3.1%, which Air Cargo News read as more cargo moving over shorter distances. In mid-September the carrier said it was adding transpacific freighter capacity, with Jonathan Ng, head of cargo hub operations and development, pointing to “growth in semiconductor and data-center equipment shipments from across Asia to our transpacific markets.”

The relay is the risk

Transshipment rose 19.5% in June, according to the Airport Authority, and 18.2% in August. For the world’s busiest cargo airport that is a healthy revenue line. It is also the pattern US enforcement has started to focus on.

Since 23 December 2020, US export rules have treated Hong Kong exactly like mainland China, after the Commerce Department’s Bureau of Industry and Security (BIS) removed the city’s separate status under Executive Order 13936. A controlled chip sent to Hong Kong needs the same license as one sent to Shanghai. On 27 August, Bloomberg reported, citing people familiar with the matter, that BIS is examining 47 shipments handled in 2024 by Apex Logistics, the Singapore-based unit of Kuehne + Nagel. According to that reporting, the route under scrutiny ran Nvidia-powered servers from Taiwan to the US, then to a destination in Southeast Asia and on to Hong Kong, where the hardware was driven across the border into the mainland. Apex acknowledged US interest in “a small number of shipments that Apex handled in 2024” and said it was cooperating fully. The investigation is ongoing, and details may change.

BIS has also been tightening the paperwork. Guidance issued on 31 May confirmed that a license is required to export advanced computing items to entities headquartered in China and the other Country Group D:5 countries or Macau, or whose ultimate parent is, wherever they operate. Trade lawyers at Crowell & Moring read that as a call for “rigorous end-user diligence, including ultimate beneficial ownership analysis.”

None of this means Hong Kong’s relay traffic is illicit. Most of it is presumably ordinary trade in electronics that ends up in ordinary factories and data centers. But the policing model has changed, and it now reaches the logistics provider in the middle, not just the manufacturer at one end and the buyer at the other.

Who carries the risk

The winners are easy to name. Cathay, the airport’s cargo terminal operators and forwarders with strong compliance teams are moving high-yield cargo through a hub increasingly built on high-value, low-weight cargo. The obvious loser is the ecommerce business on Europe lanes, which the EU has priced down.

The open question sits with everyone else. A forwarder booking transit cargo through Hong Kong often never sees the end user, yet the Apex case suggests Washington is prepared to look at the forwarder’s paperwork as closely as the shipper’s invoice. According to one person cited by Bloomberg, the shipments in question were labeled by two Apex employees with a code indicating the hardware was not subject to US export controls, and both left shortly after the company learned of the probe. When transshipment grows by close to a fifth while local export tonnes shrink, that exposure grows with it.

Hong Kong has always made its living moving other people’s goods. The difference now is that Washington wants to know whose goods they are and where they end up. A relay only works if every handoff is clean.