Index index price
Price index, measure of relative price changes, consisting of a series of numbers arranged so that a comparison between the values for any two periods or places will show the average change in prices between periods or the average difference in prices between places. Meanwhile, the S&P 500 index closed down 0.4% at 2,996, slipping below a psychologically significant level at 3,000, while the Nasdaq Composite Index finished 0.7% lower at 8,104. All closing levels are on a preliminary basis.