"Every economy has problems. We have trillion-dollar deficits. That doesn't mean either economy is in fundamental danger. It's a massive miscalculation."
The Shanghai Composite Index, China's main stocks gauge, is down 23 per cent this year, making it the world's worst-performing major exchange.
But unlike in the United States, the ups and downs of the Chinese stock market affect relatively few people, meaning sell-offs are unlikely to translate into pressure on Chinese leaders.
Less than 10 per cent of China's adult population owns shares, according to Fraser Howie, the Singapore-based author of three books on the Chinese financial system. In the United States, the comparable figure is more than half, according to Gallup.
In addition, Chinese share prices move with little regard for what is happening in the real economy. In 2008, for example, stocks fell by more than 65 per cent even as the economy grew by nearly 10 per cent.
"It's wrong to think the market fully equals winning the trade war," Howie said.
Likewise, any wobble in the Chinese economy thus far has been modest. Though China has slowed from the double-digit growth rates it recorded earlier this decade, its economy grew by an annual rate of 6.7 per cent in the second quarter.
"To the extent that Trump is looking at that and thinking he has China by the neck, he's wrong," said economist Andrew Polk, a partner at Trivium, a Beijing-based advisory firm.
"China's economy has its own issues. It's slowing down, but it's not about to blow up. Trump has less leverage than he thinks."
The president has imposed tariffs on US$50 billion ($76b) worth of Chinese imports, mostly industrial goods, and says he will soon slap levies on an additional US$200b. American consumers will feel the sting of that move as prices rise for Chinese-made refrigerators, air conditioners, furniture and clothing.
Trump says the tariffs are aimed at compelling China to abandon a host of unfair trade practices, including forcing US companies to surrender their trade secrets in return for access to the Chinese market.
The Chinese government has retaliated with equivalent tariffs, targeting American agricultural products in politically important states ahead of the November congressional elections as well as American multinationals with factories in China.
On Thursday, the largest US business groups in China pleaded with Trump to cease fire. Nearly two-thirds of more than 430 US companies in China say the duties Trump imposed this summer have damaged their businesses, according to a survey by the American Chamber of Commerce in Beijing and Shanghai.
Nearly half of the respondents - in retail, food and manufacturing - reported that their production costs have climbed, while 42 per cent said sales were down. Just 6 per cent, meanwhile, said they would consider moving factories to US soil, an administration goal.
"The US administration runs the risk of a downward spiral of attack and counterattack, benefiting no one," said William Zarit, the president of the American Chamber of Commerce in Beijing.
Most of the tariffs that have been imposed have hit US companies, not the Chinese, according to economist Mary Lovely of Syracuse University. She found, for example, that 87 per cent of the computer and electronics parts subject to Trump's levies were produced by American companies.
Trade-war uncertainty has contributed to a cloud over Chinese investing. But this year's losses in the casino-like Chinese stock market also are nothing new - the market fell by almost half over a six-month period that ended in early 2016.
Apart from trade worries, there are a number of domestic considerations that have hurt Chinese stocks.
China's market is closely tied to the amount of money available for investing. This year, Chinese officials have tightened credit in a bid to wean the economy from its dependence upon debt-fueled growth. That's meant allowing more Chinese companies to default on their corporate debt, a change from previous years when state-owned banks would have kept them afloat.
The collapse of several peer-to-peer online lending networks also spooked Chinese investors.
The market has been hurt by concerns about Chinese companies' use of their stock as collateral for loans, which leaves share prices vulnerable if they get into financial trouble and are forced to sell. Chinese financial institutions had nearly US$220b in such loans at the end of July, down about 8 per cent from the recent peak in January, according to Bloomberg.
"China's markets have dropped by close to 25 per cent," Trump said at the White House last week.
"Their markets have gone down. I don't like to see that. But I can tell you that the United States has picked up about US$10 trillion in worth. And China would like to be in our position. They would like to be in our position."
But the president's repeated crowing about China's financial woes is contributing to a nationalist backlash that may prolong the dispute, with the Chinese concluding that Trump is seeking more than just a level playing field for trade.
"The way we're going about it makes it harder for Chinese leaders to make concessions," said David Loevinger, a former financial officer at the US Embassy in Beijing. "The US has a one-pronged strategy - keep raising the pain threshold until the other side cries uncle."
Some of the president's top advisers see the financial market slump as a reflection of broader economic problems in China. "What are these stock markets telling you?" Lawrence Kudlow, director of the National Economic Council, said on CNBC last week. "China is moving lower in their economy. The US is moving higher. We're the hottest place in the world."
It is true that the US economy is hitting on all cylinders. The 3.9 per cent unemployment rate is approaching half-century lows, while the expansion that began in June 2009 shows no sign of losing steam. Optimism among small-business owners recently hit a 45-year record.
"The Economy is soooo good, perhaps the best in our country's history (remember, it's the economy stupid!)," Trump boasted earlier this week on Twitter.
China's gradual slowing comes as the government is attempting to engineer a shift from growth based on heavy investment in infrastructure and exports to an economy powered by domestic consumption, according to William Overholt, a senior fellow at Harvard University's Asia Center.
Uncertainty arising from Trump trade policies will lead to a global slowdown in growth next year, according to BNP Paribas. The bank's latest forecast, released this week, calls for China's economy to grow at an annual rate of 6.1 per cent next year vs. 1.8 per cent for the United States.
Many analysts point to drops in retail sales and investments as an indication that China's economy is downshifting.
But Nicholas Lardy, a China expert at the Peterson Institute for International Economics, said he doubts the economy is genuinely slowing.
The Chinese government is changing the way it collects and reports key economic data, including retail sales and investments, making it difficult to draw conclusions.
But China imported almost 19 per cent more goods in August than it did in the same month last year.
"The underlying demand in the economy is fairly strong," Lardy said.
The administration's confidence that China is being hurt also overstates the country's dependence upon trade, he said.
Since the 2008 financial crisis, China has reduced its dependence upon trade by one-third, according to Lardy.
