LME wharehouse copper stocks have risen from 250kt to 312kt in...

LME wharehouse copper stocks have risen from 250kt to 312kt in last 3 weeks with price reacting accordingly.

ie 24.8% increase in stock, in 3 weeks.

Here is the reason, from
reuters.

By Harpreet Bhal.

CHINA EYED
Looking ahead to 2013, Strachan said investors are likely to focus on the outlook for demand from China, which has remained soft this year.
"There has been a recovery in the Chinese economy, but it is weaker than many seem to believe. We think Chinese demand (for copper) is going to be much weaker than people expect because of the high stock levels," Strachan said.

In China, the world's top copper consumer, stocks in bonded warehouses have swelled due to weak domestic demand and could dampen the country's appetite for imports in coming months.
China imported 250,666 tonnes of refined copper in November, down 27 percent

from a year earlier, although imports over the 10 months to end-November were
still up 30 percent on the year at 3.16 million tonnes.