http://asia.nikkei.com/Politics-Economy/Economy/Market-awaits-Chi...

http://asia.nikkei.com/Politics-Economy/Economy/Market-awaits-China-stimulus-as-more-defaults-loom

in part....

" Some companies raise funds via copper, using export letters of credit to import the metal, which is then posted as loan collateral.

Falling copper prices and investment product defaults both signify a tighter funding environment for businesses, and both can be viewed as stemming from the same source. With the fuss over wealth management products at the end of January, banks are exceedingly cautious about lending. The country's total social financing, a measure of overall credit growth, came to 938.7 billion yuan ($152.95 billion) in February, well below January's 2.58 trillion yuan, the People's Bank of China announced Monday."

From Kitco site.