Investment funds believe that there's more move on the upside.

Zinc prices are up on low capacity utilization rates at Chinese zinc smelters due to concentrate shortage, and strong demand driven by galvanized steel.

Supply concerns at the forefront of market attention and any threats to production are feeding straight through to price.

The prospect of demand growth and low inventories will continue to drive prices going forward.

Besides, an increasing number of strikes have lead to disruptions in supplies.

I think we are still in the early stages of the bull trend in copper. We have years of strong prices ahead of us.

There are many supporting factors. The uptrend will remain in place.

In this situation, where you have strong global growth, constraints on the supply side and a general decline in inventories, prices will continue higher.

The lower numbers we have seen have attracted buying interest from a combination of end-users and speculators particularly from China.