Indian equity benchmarks Sensex and Nifty closed marginally lower on December 30, a day marked by volatility and caution ahead of the US Federal Reserve's minutes release and year-end thin volumes. While auto, metal, and PSU Bank indices saw gains, the IT sector dragged the market down. Several individual stocks experienced significant movements due to specific corporate developments, including order wins, credit rating upgrades, and approvals for new facilities or bonus issues.