Indian stock markets opened marginally higher on Tuesday before the Christmas holiday. The chances of a year-end rally are diminishing due to consistent pressure in the markets. The Nifty 50 index opened at 23,769.10 points with a marginal gain of 15.65 points or 0.07 per cent, while the BSE Sensex opened at 78,707.37 points, gaining 167.20 points or 0.21 per cent.