Copper futures rebound from intraday lows near $6.4955 to erase most of the day's losses, supported by lower Treasury yields and tame inflation data. July Producer Price Index (PPI) figures come in flat, maintaining expectations for a Federal Reserve rate hold in September and pulling Treasury yields down 5 to 7 bps across the curve. In supply news, Reuters reports China's refined copper output is expected to drop in August for a second consecutive month due to tight concentrate supplies, though softening physical demand from the region continues to offset supply concerns.