If a twenty-two-year-old invested $10,000 in the S&P 500 index in January 1980, she would have a retirement nest egg of well over $1 million today (assuming reinvestment of dividends along the way). If that same person invested just $100 per month after the initial investment, she would have a portfolio of well over $2 million today. If she ratcheted up her monthly investment to $1,000, she would have a portfolio of over $10 million today.
