Just to put this in perspective this 30% drop is a $3 trillion dollar loss.  Most of the investors are small and have bought on margin using property as collateral.  China was trying to move state run economy in to private investors. They encouraged the people to invest.  It looks a lot like 1929 in China.  

Which is why Beijing has been throwing everything at trying to find a way to end the rout - including cutting the cost of money - and has been failing miserably.

One of the so-called solutions to this market disaster is that an astonishing 1301 companies have had trading in their shares suspended. Their prices can't fall any more because the shares can't be bought or sold.

But this means that a further $2.6 trillion of wealth, tied up in these shares, is completely frozen - which adds insult to investors' capital-loss injury.

http://www.bbc.com/news/business-33440565 

This is the world's second largest economy.  The question now is this going to spread or be felt outside of China?  

On Monday, China’s state media had vowed that a government action plan, including a forced pause in initial public offerings and a scheme by which top brokerages would spend nearly $20 billion to shore up the market, would reverse “fragile market sentiment.” Beijing’s unprecedented intervention dwarfed even the U.S. government’s TARP financial rescue plan. But by Wednesday, the nation’s security regulator was warning of “panic” by spooked investors. Beijing’s involvement didn’t seem to be working.

http://time.com/3949062/china-stock-market-shanghai/