At 125 years, the Dow is more relevant than some investors might think

The Wall St. sign is seen near the New York Stock Exchange (NYSE) in New York City, May 4, 2021.
Brendan McDermid | Reuters

Nineteenth-century blue chips like U.S. Leather and American Cotton Oil are long gone, but the Dow Jones Industrial Average lives on, celebrating its 125th year on Wednesday.

Apple, Boeing, Intel and Honeywell are among the current Dow 30, representing industries that didn't exist when the Dow was launched on May 26, 1896, with a dozen industrial stocks. Charles Dow, co-founder of Dow Jones Co., created the index as a complement to his 12-year old transportation index, made up of mostly railroad companies.

"It's still probably the world's most well-known index and when someone says, 'How's the market doing?' and it's up 300 points, everyone knows it's the Dow, which is pretty amazing given how little is indexed to the Dow," Wharton School professor Jeremy Siegel said.