Nuvama raised concerns over Oil and Natural Gas Corp.'s volume guidance and expects next year's earnings to be impacted if crude oil prices decline further. Jefferies has a cautious view on markets in the near term, as its count of 'underperform' ratings on companies has doubled.NDTV Profit tracks what brokerages are putting out on stocks and sectors. Here are all the top calls from analysts you need to know about on Wednesday.