Offer your thoughts or opinion on the input financial query or topic using your financial background.

Is compounding interest on investments a myth?
The S&P 500 index from 1974 to present certainly looks exponential to me (1974 is the earliest data Google has).  If you read Jeremy Siegel's book there are 200 year stock graphs and the exponential nature of returns on stocks is even more evident.  This graph only shows the index value and does not include the dividends that the index has been paying all these years.  There is no doubt stocks have grown exponentially (aka have grown with compound interest) for the past several decades and compounded returns is definitely not a "myth".  The CAGR on the S&P 500 index from 1974 to present has been 7.54%: (1,783 / 97.27) ^ (1 / 40) - 1 Here is another way to think about compounded investment growth: when you use cash flow from investments (dividends, capital gains) to purchase more investments with a positive growth rate, the investment portfolio will grow exponentially.  If you own a $100 stock that pays 10% dividends per year and spend the dividends every year without reinvesting them, then the investment portfolio will still be worth $100 after 40 years.  If the dividends are reinvested, the investment portfolio will be worth $4,525 after 40 years from the many years of exponential growth: 100*(1 + 10%)^40