An overweight rating on a stock usually implies that an equity analyst is sure that the stock price of a company will increase in the future. At the same time, investors need to realize what benchmark is used when comparing the performance of the stock to come up with a rating. They can utilize a benchmark index when issuing an overweight rating, which can be S&P 500. It comprises 500 of the leading companies in the United States. In short, it means that this particular stock should obtain a higher weighting compared to the current one.