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.

Short-term bearish investors can profit from declines in the Dow Jones with ProShares Short Dow30 ETF (DOG), but it's not ideal for long-term investment.

The historic addition of artificial intelligence (AI) colossus Nvidia may spell trouble for Wall Street's most iconic index.

Chip giant Nvidia will join the Dow Jones Industrial Average, the iconic Wall Street index announced Friday, underscoring the importance of artificial intelligence in the US economy.