The Dow Jones Industrial Average has undergone many changes since its lengthy history. The index has been tracking 30 companies for more than a century, and recent changes have strengthened it. The Dow Jones has recently been kicking out underperforming stocks and replacing them with big tech companies.Concentrating on the Magnificent Seven stocks has been a winning formula for several years. There is a fund called the Roundhill Magnificent Seven ETF (NASDAQ:MAGS) that only has the Magnificent Seven stocks. ...