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.

Also know that, unlike the S&P 500 or the Nasdaq Composite, the Dow is weighted by price rather than by market cap. Although Nvidia has an outsized influence on the movements of the cap-weighted benchmarks, at current prices NVDA stock will be as important to the DJIA as, roughly, 3M ( MMM ).