Stock markets experienced a difficult trading week as the indices closed trading in the red after erasing the gains from the week. The BSE Sensex closed the last trading session at 72,485, down by over 450 points, while the NSE Nifty50 stood 123 points lower at 22,023. In the week ahead, investors will keenly be on the lookout for foreign fund flows, rupee-dollar movements, the outcome of the US Fed policy rate meeting, along global trends.