Monday sees the release of China's GDP figures, and they will be even more watched than usual.
Apple CEO Tim Cook blamed cautious Chinese consumers in part for his company's failure to sell as many iPhones as it had hoped, pushing stock prices down around the world.
Sales of cars in the country fell for the first time in two decades.
Behind such evidence, investors and policymakers are increasingly worried about the state of such a crucial engine of global growth.
How worried should they be?
Measuring the output of an economy is never easy, but China's data comes with a greater health alert than most.
Instead of 6.5%, independent economists say the value of GDP may be closer to 5% – or even lower.
Xiang Songzuo, a professor of finance and former chief economist at China Agriculture Bank, said growth of 2018 may have been only 1.7 percent.
His online video has already been censored by the authorities.
The unreliability of official figures is one reason why other indicators, such as Apple's sales, have the power to send shockwaves to global stock markets.
It may be difficult to confirm the scale of the slowdown in China, but it is clear that growth has slowed.
It has recently been revealed that factory and workshop activity stagnated for the first time in two years in November.
In the following month, exports fell by 4.4% in relation to the previous year. Chinese households are clearly feeling the pinch: retail sales are growing at their lowest rate in 15 years.
Is the deceleration intentional?
Partly, possibly. After establishing itself as the world's workshop for the last forty years, China found itself losing its competitive advantage to the Philippines and Vietnam, where labor is even cheaper.
The government has decided to shift the focus of exports to increasing domestic demand.
However, concerns have arisen over the size of China's debt stack – and the risk of bad loans.
Among them, the country's families, government and corporations have debts that amount to almost triple the size of GDP.
A credit crunch seems to have been heavy on spending and investment. And then there's the trade war with the US.
Although there has been an initial flood of requests to circumvent tariffs, the latest export data suggest that such measures are harming Chinese producers.
While the government has introduced measures to support the economy, most economists expect China's growth to fall further.
How much does it matter to the UK?
In terms of our exports, China is the UK's sixth largest trading partner. We sell them more than 22 billion pounds worth of goods by 2017 – with cars, medicines and oil-based products making up the bulk.
Politicians have pinned their hopes on a closer trade relationship with China in the post-Brexit era.
But the demand may not be as strong as they are anticipating.
Then there are billions of pounds of Chinese companies and entrepreneurs who invest in the UK every year – 20 billion pounds in 2017 alone.
Thames Water, Pizza Express and West Bromwich Albion FC are among the many who enjoy Chinese support. This type of investment is notoriously volatile.
And let's not forget the worries about bad loans. There is good reason why Bank of England Governor Mark Carney cites China as one of the biggest risks to global financial stability.
Several major banks, such as HSBC and Standard Chartered, have significant exposure to this market.
What are China's long-term prospects?
Since 1980, growth (if official numbers are believed) has averaged more than 10% per year, which means that the size of the economy has risen 42-fold over this period.
China's time in the sun, the surge of superhuman growth, may be over.
By 2030, economists say growth will have shrunk to about a third of its current figure.
But even that would be enough to ensure that the US will rise above pole as the world's largest economy.