Nvidia is now worth as much as the whole Chinese stock market

The issue is with the title, not the article.

In the article, they refer repeatedly to the "Hong Kong stock exchange", not the "Shanghai stock exchange" or the "Chinese stock market".

Could it be that the article was originally titled "as much as the whole Hong Kong stock market", but the reviewer worried it implied that Hong Kong is independent from China; so they changed it to a `safer` but less accurate title?

It's misleading and many other outlets are repeating the same thing. The total joint market capitalization of listed domestic companies for China was about 12.5 trillion as of 2020 [0] and approximately 78.8 trillion yuan [1] (about 10.90 trillion USD) in 2022 from just looking at freely available data. I'm fairly sure the original source of this statement, Michael Hartnett (chief investment strategist at Bank of America), is well aware of that. It's a purposefully deceiving claim and outlets just repeat it without proper context.

0. https://data.worldbank.org/indicator/CM.MKT.LCAP.CD?location...

1. https://www.statista.com/statistics/235090/market-capitaliza...