India, Oct. 15 -- A refinery is a simple machine with a complicated business around it. It buys crude, turns it into petrol, diesel and chemicals, and earns the gap between what comes in and what goes out. That gap moves with crude prices, product demand and government levies, which is why refiners' profits can jump or slump from one quarter to the next. Revenue alone tells you very little about how a quarter really went.

The Nifty 50 traded at 23.038.85, up 1.83%, while the Sensex rose 2.03% to 74,254.91 on Wednesday. Meanwhile, Shares of Mangalore Refinery And Petrochemicals were trading at Rs. 176.80, down 4.53% from previous close of Rs. 185.26. The stock opened at Rs. 189.60 and reached an intraday high of Rs. 191.49 and low of Rs....