Amazon to join the Dow Jones index, while Walgreens gets the boot. Here’s what that means for investors. [Video]

Amazon.com is being added to the Dow Jones Industrial Average, joining Apple, Walt Disney, Walmart and other companies that make up the 30-stock average.

The e-commerce giant will replace drugstore operator Walgreens Boots Alliance in the Dow before the open of trading on Monday, S&P Dow Jones Indices said Tuesday.

The shift was prompted by Walmart’s decision to do a 3-to-1 stock split, which will reduce its stock’s weighting in the index. The Dow is a price-weighted index, so stocks that fetch higher prices are given more weight.

Seattle-based Amazon will join the Dow on the same day that Walmart executes its stock split.

“Reflecting the evolving nature of the American economy, this change will increase consumer retail exposure as well as other business areas in the DJIA,” S&P Dow Jones Indices said.

Amazon’s entry into the Dow, Walgreens’ exit and Walmart’s stock split will cause a ripple effect on …