The market is uncertain but sometimes fortune turns in seconds. The same happened today as the markets closed for the week. While the whole week was positive till this morning, the trading session closed negative for both the benchmark indices. The Sensex went down by 6.78 points or 0.02 per cent to stand at 36,541.63 and the Nifty lost 4.30 points or 0.04 per cent to close at 11,018.90.