The most genuine answer should be 'INVEST IN WHAT YOU KNOW'. The sector which you have the best knowledge will give you amazing results.If you are working in Automobile Industry, then you would have good knowledge of which company's market share in passenger/commercial vehicle segment is increasing or launching a new car with huge sales potential. You would also know suppliers of these big companies. Like which company produces Battery, Seats, Glasses, steering wheel etc and which one is best among them. By using what you already know, you can easily select the best company.Similarly, if you are working in a pharmaceutical company, you will have good knowledge of which new company is producing a new drug, which may revolutionize the industry and can bring a great increase in sales and revenue of the company, once patented.Overall, investing in the sector which you already know is the best option.Nevertheless, personally, I am bullish on NBFC (Nonbanking financial company), Infrastural companies and Automobile accessories. However, I have also bought the stocks from other sectors like FMCG, Consumer durables, Oil & gas etc to diversify my portfolio. As elders say- "DO NOT PUT ALL YOUR EGGS IN THE SAME BASKET".I hope it helps. Happy Investing.