The long history of the venerable Dow Jones Industrial Average dates back approximately 130 years. In that time the Index has changed some of its components 58 times. While this has the appearance of stability,

A $1 gain in UnitedHealth would represent only a 0.18% change for the stock, compared to a significant 4.31% move for Intel. For Nvidia, a $1 change would be about 0.74%. Despite these percentage differences, the effect on the Dow remains the same. A $1 move in any Dow stock translates to roughly 6.6 points on the index.

Business Insider's Emma Cosgrove explains why Nvidia is now seen as a bellwether and what the switch says about the whole AI ecosystem.