Recently, we took a look at the S&P 500 which included a great visualization of the market cap of companies that make up the index.

To many in the investment world, the stock market is still on its bull-market run (though there is some disagreement on the technical length of it). This means that companies which make up the index have grown in value as a whole. Individual companies have jockeyed for position with some being added to the list of largest 500 companies in the U.S. while others have fallen off.

Josh Wolfe brings us another great visualization comparing the 10 largest companies in the S&P 500, from March 2009 to August 2018.

Time surely flies, and there are so many historical lessons gleaned from market data. Arguably none more obvious than the rise of Amazon. But what about the tumultuous decade that Bank of America experienced? Or the fall of IBM, relatively speaking? Only three companies in the top 10 in March 2009 remained there in August 2018.

Perhaps the most simple lesson learned from a chart like this is that we don't know what will happen in the future. What we believe to be the best companies at the current time may fall off in the not-too-distant future. Companies that we don't yet know anything about or are not evenly publicly traded may one day dominate the headlines and market share.