Let's say that you want to calculate the return of the S&P 500 index during the month of October 2015. First, using an accurate price chart, determine the starting and ending price. In this case ...

Image source: Getty Images. In practice, using a price-weighted average to calculate a stock index means that the higher-priced stocks disproportionately influence the index's performance.

The index is published monthly by the U.S. Bureau ... the overall monthly change in final demand PPI. The indexes calculate price changes in private contracts based on suppliers' input prices.

The Price Kaleidoscope shows you the price trend and the weights of various product groups in the consumer price index. You can use this calculator to show the price development while weighting the ...