stock index(redirected from Securities Index)
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A group of stocks put together in a standardized way to provide a useful window into a sector or market's performance at a glance. That is, a stock index groups together a certain list of stocks and usually takes an average of their prices so as to provide an idea of how the industry or market represented in the stock index is doing. Very often, stock indices are weighted to prevent a few data points from overwhelming it. For example, the S&P 500 is weighted according to market capitalization, while the DJIA is weighted for price.