Indian stock markets showed mixed performance midday on December 30, with the Nifty 50 and BSE Sensex trading cautiously. Hindustan Copper shares surged over 6%, continuing an eight-day rally driven by rising copper prices. In contrast, Dixon Technologies shares fell to a 52-week low, impacted by concerns over electronics manufacturing outlook and import norms. Shriram Finance shares rose over 2% following a credit rating upgrade.