Shanghai Futures Exchange copper futures lower amid weak sentiment, tracking overnight losses in LME 3-month; "rising warehouse stocks and weak technicals will probably pressure LME 3-month copper further in the short term," says Shanghai trader. Adds if favorable data indicating resumed Chinese buying, good U.S. economy do come in March, April, such downward trend might then be considered "over-corrected". Benchmark April contract at CNY50,280/ton, down CNY730. LME 3-month at $5,400, down $20.