Most indexes, like the S&P 500 and Nasdaq Composite, assign a higher weighting to the largest companies by market cap. For example, Apple has roughly 11 times the market cap of Coca-Cola, so it has a much higher weighting in the S&P 500. But in the Dow, Apple is the 12th highest-weighted company by market cap because the index is price-weighted.

The ins and outs of membership in the 30-company group that represents success across industries and reflects stock market conditions.

Nvidia joins the DJIA amid cyclical highs, but past trends suggest caution. Find out why NVDA stock may struggle despite the prestigious inclusion.