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Money lessons you can play with
Five ideas that change how you see money. Each one is interactive, so move the sliders and watch it work.
Lesson 1
The Rule of 72
Divide 72 by your yearly return to estimate how many years it takes your money to double. It's a mental shortcut for comparing savings accounts, loans and investments.
Your money doubles in about
years
Lesson 2
Starting early beats investing more
Ana invests from age 25 to 35, then stops completely. Ben starts at 35 and invests every month until 65, three times as long. Who has more at 65?
Ana: 10 years (25–35)
Ben: 30 years (35–65)
Lesson 3
Small fees, huge costs
A 1% fee sounds tiny, but it's charged on your whole balance every year. Compare an index ETF (0.03%) with a typical actively managed fund.
Lesson 4
Cash slowly melts
Inflation is running at 3.4% right now. Money sitting in a 0% checking account loses buying power every year. A high-yield account paying near the T-bill rate (4.23%) keeps up much better.
Lesson 5
ETFs vs mutual funds vs single stocks
ETFs
A basket of stocks that trades like a single stock. Index ETFs (VOO, VTI) are diversified, very low-cost and tax-efficient.
- •Fees from 0.03%
- •Buy anytime the market is open
- •Instant diversification
Mutual funds
Pooled, often actively managed portfolios priced once a day. Common in 401(k)s. Index versions are cheap, but some charge loads and high fees.
- •Automatic investing is easy
- •Watch for loads and 12b-1 fees
- •Often minimums ($1k–$3k)
Single stocks
Owning a piece of one company. Bigger potential upside, and bigger risk: even giants can fall 50% or more.
- •No ongoing fees
- •Dividends possible
- •Concentration risk
Real 10-year average yearly price returns
From our stored daily history. Dividends are not included, and past results don't predict the future.