How often are the S&P indices updated?

The S&P indices are updated on a variety of frequencies depending on the specific index. However, most of the major indices, such as the S&P 500, are reviewed and rebalanced quarterly. This means that the composition of the index, including the stocks that are included and their respective weights, is assessed and adjusted every three months. Additionally, there are instances when a company within the index undergoes a significant event, such as a merger or bankruptcy, leading to its removal or replacement outside the regular rebalancing schedule. In such cases, the index may be updated immediately to reflect these changes. Overall, S&P strives to ensure that their indices accurately represent the market and are regularly maintained to reflect the evolving dynamics of the underlying companies.