I believe much of the turnover in the major stock market indexes comes from mergers and accusations, rather than companies failing. Sometime it is a floundering

I believe much of the turnover in the major stock market indexes comes from mergers and accusations, rather than companies failing. Sometime it is a floundering company that is acquired, but often it is companies seeking to expand their markets or vertically integrate. I had a profitable petroleum refining company in my equities portfolio that has been gobbled up and issued a new ticker symbol four times in about five years.