And now, that may be getting them into trouble,

which could mean trouble for the rest of us too.

Chinese companies owe the biggest pile of corporate debt, in the world by far,

about 18 trillion US dollars, or a 170 percent of Gross Domestic Product.

In the first 3 months of 2017, companies defaulted on 9 of the bonds they have issued.

Not a big number, but a record for the first quarter.

The danger is, that the Beijing tries to pare back credit growth in the economy,

many companies will become unable to honour bond payments or repay bank loans.

This frailty is already causing ripples, in a skittish Hong Kong stock market.

Huishan Dairy, a Chinese company that was late on loan payments, have 4.1 billion US dollars

wiped of its market capitalization in March.

A debt crisis in China will certainly shake the global economy.

Chinese companies, which of financing themselves from precariously leveraged balance sheets,

are acquiring firms in Europe, the US, and elsewhere.

Will boom turn to bust in China?

Some Chinese companies are now defaulting on their bonds,

if the number continues to grow, it's time to worry.