Everybody saw the crash coming. It was clearly a bubble as the Shanghai Stock Exchange went up 250% in 12 months while every indicator (company profits, manufacturing prices, etc) were showing bad news.
https://au.finance.yahoo.com/q/bc?s=000001.SS&t=5y&l=on&z=l&...
Stock exchanges don't double in price year over year on bad news. That's just stupid.
I'm surprised the SSE has only fallen 30%. It still looks like it needs to lose another 30% (it's still up nearly 100% since early last year).
The only reason the entire world isn't shorting Chinese stocks is it's tricky to fight deliberate market manipulation by the Chinese government. Although I don't doubt this crash has made a few people very rich.