If Donald Trump wanted to shore up America’s national security with his Thursday night executive orders pinpointing two Chinese apps, he has certain not achieved much. On the other hand, if he wanted to send a political message, and make it perfectly clear that China’s technological rivalry with America comes at a price, he succeeded hands down.

The shares of Chinese entertainment and tech firm Tencent dived on Friday just hours after Trump issued an executive order banning the company’s emblematic WeChat messaging app in the U.S., starting 45 days from now.

The Hong Kong-traded stock finished the day 5.04% lower, at HK$527.5, having at one point been more than 9% down. As the largest component in the Hang Seng Index, Tencent’s plunge helped drag down the wider Hong Kong stock market by 1.6% on Friday to 24,531.62.

Earlier in the week, buoyed by China’s gathering economic recovery, and its own digital prowess, Tencent had seen its stock reach an all-time high of HK$559. That had been enough to overtake Facebook and make Tencent the world’s seventh largest corporation.

The $35 billion decrease in Tencent’s value that Friday’s fall represents is massively out of proportion to the loss that the company could possibly suffer from WeChat simply being shut out of the U.S. The New York Times reports that WeChat has approximately 4 million users in the U.S. – compared with the messaging app’s 1.2 billion monthly average users worldwide.

It is not even clear what the executive order intends by the phrase “transactions related” to WeChat. Does it mean that it would be illegal for existing U.S. WeChat users to send or receive messages? Does it mean that WeChat and TikTok must be removed from U.S. app stores? Do they have to be removed from the overseas app stores of U.S. corporations such as Apple and Google?

But even with a sideswipe at an icon of Chinese tech, one that every adult in China is utterly familiar with, Trump has delivered a message that has been heard in Shenzhen, China’s other tech hubs in Hangzhou, and the national capital Beijing.

“The U.S. is using national security as an excuse and using state power to oppress non-American businesses,” China’s Foreign Ministry spokesman Wang Wenbin, said at a Friday briefing. “That’s just a hegemonic practice. China is firmly opposed to that.”

TikTok has threatened to use the U.S. justice system to halt the Trump-mandated sale of its U.S. operations.

The new executive orders inevitably increase investors’ expectations that China will retaliate against U.S. companies or interests – just as China last month retaliated against the forced closure of its consulate in Houston with the shut-down of the U.S. diplomatic outpost in Chengdu, and as the two countries are engaged in a battle to expel many of each other’s journalists.

Might China now kick the U.S. tech firms out of Hong Kong? There they currently sit on a knife edge, subject to the new National Security Law, but so far not co-operating with police requests for data.

“It seems likely that tensions will ratchet higher ahead of U.S. elections, a factor that could play badly for risk assets,” said Mitul Kotecha, senior emerging markets strategist at TD Securities, quoted by Reuters.

While WeChat’s U.S. operations are puny, Tencent has much to fear from a trade-, tech-, or Cold War between the U.S. and China. It is one of the largest Chinese investors in Hollywood, and has stakes in businesses including Riot Games, Epic Games, as well as lesser known gaming businesses TiMi Studios and LightSpeed LA.

U.S. tech firms, though largely banned or absent from direct to consumer sectors, also have much to fear from China’s retaliatory moves. Microsoft maintains a large R&D operation in China. And Google and Facebook both sell ads displayed outside China on behalf of Chinese client corporations.

Tencent’s Friday tumble dragged down Hong Kong’s one week old Hang Seng Internet & Information Technology Index by 2.21% to 4,695.94.

The index is stuffed full with mainland China’s most prestigious tech companies – electric car maker BYD, consumer services giant Meituan-Dianping, phone equipment maker ZTE, and chip-maker SMIC – all of which may be feeling increasingly unwelcome in the U.S. The index also contains companies like e-commerce titans Alibaba and JD.com that have recently given their shares secondary listings in Hong Kong in case American securities regulators turn nasty against New York-listed Chinese equities.

The new HSIIT Index then represents a list of targets for Trump’s next moves.