US COMEX copper futures for September delivery settled up 6.05 cents at $3.5345 a lb on Thursday, after hitting a high at $3.545, the highest price since July 3. Trading volume was heavy during Thursday's rally at 40 percent above its 250-day average, preliminary Reuters data showed. Traders now look forward to Friday's US Commitments of Traders report which will show managed money's net length in the copper market.
The metal is up just 2 percent this year, however, having dropped sharply in the second quarter amid concerns over Europe's debt crisis, slower growth in China and a stalling recovery in the US.