Ok, you've convinced me that the Chinese stock market crash could be localized to China and Southeast Asia. What would it take to increase the chance of this turning into a fully-fledged global meltdown?
Purely for research purposes of course
So, three things (the first, concerning; the second, fucking terrifying):
1. Hong Kong and Taiwan are in that weird sort of position of being China-but-not-China. The Hang Seng closed down 6% today alone. The HK and the Taiwanese markets ARE fully integrated into the world economic landscape and DO have foreign investors. A lot of that FDI we discussed (I don't have the numbers in front of me, and some of them may even be "state secrets") is from Taiwan and Hong Kong, because they don't have some of the same restrictions on investment that say, American, European, or Japanese investors do. So there is a potential contagion to those two countries, which could in turn trigger a cascade effect.
2. If enough people lose enough money and get pissed off enough about it, there could be civil unrest. This is the nightmare scenario for every government of China ever. And why they're so slow in trying reforms. And why you're seeing a confusing and somewhat counter-productive government response, which has ranged from attempts to freeze the market, to halting all IPOs for the next six months, to ordering all state-owned enterprises to not sell any shares, to government purchases of suffering stocks to slow down the crash, to editorials in government-sanctioned media outlets accusing foreign governments (specifically Japan) of "meddling" in China's markets.
Widespread civil unrest in China would have a serious negative effect on the Chinese economy, which would have major implications on the export economies of...well, just about everybody. Chinese imports plummet, rest of the world's economy goes to shit in months.
The thing is, trying to keep the stock prices where they were is unsustainable and a bad idea. They need to have an exit strategy for a lot of the retail investors so they can get out without losing TOO much money.
Here's the thing: the government *wanted* the population putting money into the stock market to make it grow. The problem is that everyone raced in, in a chance to get rich (if you think America is the land of "get rich quick" schemes, you ain't seen nothing like China) and overheated the market. It's like "Hmm, I wish our campfire was bigger. Hey, I'll let anyone who wants to be warmer throw a stick on the fire and stand here too." And then 800 million sticks later, OH GOD WHY IS EVERYTHING BURNING??!
The real concern domestically for China is that people were doing some rather foolish things (not unlike Americans at time), such as taking out loans to get more money to put into the stock market. Now their stock is worth way less than the loans, and they're deep in debt. Not everyone was doing this, and traditionally stock investing has been seen as something more akin to gambling than economics. So the average Chinese family historically hasn't held much stock, in the same way that a lot of Americans play the lottery, but only the truly stupid and/or desperate go cash in their entire paycheck and blow it on Powerball tickets.
But there's some question as to whether that might have changed over the last year, when money was seemingly pouring from the sky and people were getting rich overnight. The allure of 150% annual returns might have prompted risky behavior from a traditionally fiscaly conservative population.
If a lot of those families did in fact cash in hard assets and leverage themselves to go all-in on the Shanghai, this could have long-lasting effects.
But if (as I'm thinking and hoping) it was mostly the twenty-something IT crowd (who have a lot of money, comparatively speaking, and are looking for ways to spend it), then it won't be as bad for the country overall. Sucks hardcore for them, but they have time to rebuild. GenX'ers didn't get burned as bad in the US dot-com bubble in part because we didn't have the money to really sink into it, and because we were all probably too stoned or slacker to get involved.
In the long run, this could be a good lesson for a Chinese population still learning the nuances of market capitalism.
3. And then there's just the good old-fashioned market panic. Even though the Chinese market crash should be mostly self-contained, even seasoned investors in the West aren't always aware of conditions. They just read a story, see "$3.5 trillion dollars lost on Shanghai market in last month" and go "Holy shit, I better move some of my money into bonds and commodities. And maybe pull out of emerging market funds too, those countries just don't know what the hell they're doing". And there seem to be a lot of Western outlets publishing shallow, sensationalist coverage of this because they'd rather have click-bait revenues than calm the markets down.
Markets are fundamentally about herd mentality. Learning to predict the herd can make you a fortune. Misreading the herd can get you trampled. And panicking the herd gets EVERYBODY trampled.