The exclusive blue chip index is making some big changes.It was bound to happen at some point.On Friday after the close of trading, S&P Global announced that Nvidia (NVDA 2.84%) would finally join the Dow Jones Industrial Average (^DJI 1.02%). The AI chip juggernaut has been the most valuable company that's not included in the blue-chip index for most of this year, and with its valuation hovering north of $3 trillion, it's now challenging Apple for the title of most valuable company in the world.As seemed l ...