Dow Jones Industrial Average

A price-weighted average(not often seen as most stock indexes are market-cap weighted nowadays) invented in 1896 that is composed of 30 stocks traded in the US, usually blue chips and encompass many sectors. It is one of the oldest and most quoted indexes in the world.

Out of the twelve original components, only General Electric has survived(the rest have mergered or disappeared), which is a case for “survivorship bias” which some academics believe in.