Investing 101: Compound Interest Bootcamp

"Life is like a snowball. The important thing is finding wet snow and a really long hill."
— Warren Buffett

Part 1: The Race

Imagine two high school seniors:

  • Student A invests $200 a month starting at age 18. They stop at age 28 (only investing for 10 years). Total money put in: $24,000.
  • Student B waits until age 28 to start investing $200 a month, and keeps doing it until they are 65 (investing for 37 years). Total money put in: $88,800.

Question: Assuming an 8% return, who has more money at age 65? (Type A or B)

Part 2: The Vocabulary of Wealth

Principal: The initial chunk of money you start with on day one.
Contributions: The amount of money you add regularly (weekly, monthly).
Interest Rate: The percentage your money grows each year. Historically, the S&P 500 averages about 8-10% per year over long periods.
Time Horizon: How many years you leave the money alone to grow.

Match the scenarios to the correct vocabulary term:

1. The 9% average growth your account experiences: 2. The 40 years you leave the money alone until retirement: 3. The $500 graduation gift you open your account with: 4. The $50 you automatically transfer from each paycheck:

Part 3: The Rule of 72

Want to know a mental math trick billionaires use? It's called the Rule of 72. It tells you approximately how many years it will take for your money to double based on the interest rate.

Years to Double = 72 ÷ Interest Rate

Your Scenario: If you invest in an index fund that averages a % return...

How many years will it take for your investment to double?

Part 4: Build Your Opportunity Cost List

Opportunity Cost: What you have to give up to buy what you want in the present. Spending $10 today doesn't just cost $10—it costs what that $10 could have become if you invested it.

What are some habits or treats you regularly spend money on? Add them below.

costs $
"Compound interest is the most powerful force in the galaxy."
— Anonymous

Part 5: The Simulator Gauntlet

You now have access to the Compound Interest Simulator. Use it to answer the 5 questions below to unlock the final Sandbox. (Round answers to the nearest whole dollar)

1. The Baseline: Start with $0. Contribute $100/mo at an 8% return for 40 years. Total Value?
$
2. The Cost of Waiting: Change the years to 30. What is the new Total Value?
$
3. The Better Return: Put the years back to 40. Change Rate to 10%. Total Value?
$
4. The 50-Buck Difference: Set Rate back to 8%, Years to 40. Change monthly contribution to $150. Total Value?
$
5. The Millionaire: Keep 8% and 40 years. Play with the Monthly Contribution until the Total Value hits exactly $1,000,000 (or as close as you can get). What monthly contribution did you need?
$

Total Value

$0.00
"The best time to plant a tree was 20 years ago. The second best time is now."
— Chinese Proverb

Part 6: Free Play Sandbox

You've officially completed the bootcamp! Show your teacher your screen if they need to check you off. Otherwise, you are now free to experiment with the simulator below. Dream big, try out different monthly contributions, and see what it takes to hit your own financial goals.

Your Future Wealth

$0.00