Dow Jones Industrial Average or Dow 30 is an important Stock Market Index based on Top 30 Companies in the United States. The Dow Jones Industrial Average (DJIA) is a price-weighted index and it’s not calculated based on the weighted average market cap of companies.
The weighting methodology of Dow Jones is based on the price of Dow 30 Stocks adjusted by dividend and stock splits. The weight of Dow 30 Companies is given here as per the sectoral classification. To know the market cap and performance of Top 30 Companies check this post – List of Dow 30 Stocks sorted By Market Cap
Also, Check –
Dow 30 Weight By Sector (July 2020)