Portfolio Playground
See the ideas move
Reading about compounding, risk, and diversification is one thing. Dragging a slider and watching the numbers respond is another. These simulators turn the core ideas of investing into something you can play with.
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Growth, Savings & Debt
The engine of personal finance (compounding) in every direction: how wealth builds, how your savings rate sets your timeline to independence, and how the same math runs in reverse as debt.
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What Eats Your Returns: Fees, Inflation & Taxes
The quiet drains on your wealth in one place: fund fees (the drag you control), inflation (the one you don't), the tax drag on a taxable account, and asset location — holding the right asset in the right account. See how each compounds against you, and how to blunt the ones you can.
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Diversification
The only free lunch in investing: how mixing assets that don't move together lowers risk. From pure out-of-phase waves to messy, real returns.
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Stock-Picking: How Many, Why a Few Win & What's Fair
Hard truths about owning individual stocks: diversifying cuts risk only to a floor, most stocks lose to T-bills while a tiny few create all the wealth, a fair price swings wildly on tiny assumption changes — and options, the speculation end of the spectrum, priced so the intuition finally clicks.
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Portfolio, Allocation & Bonds
Build the actual portfolio: mix assets to find the efficient frontier, dial the all-important stock/bond split, and see why the 'safe' bond sleeve still moves with interest rates.
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Risk & Return: CAPM & Factors
How markets price risk: start with CAPM (one risk, the market's, measured by beta), then extend to the Fama–French factors that explain what CAPM called 'alpha.'
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Can You Outsmart the Market?
Five bets against the market (predicting it, timing it, deploying into it, hiring active managers, and trusting they're really active) — then the industry's own SEC-filed cash register delivering the same verdict. The whole case for indexing.
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Behavioral Finance: Your Own Worst Enemy
The market doesn't lose you money — your reactions to it do. Watch the behavior gap open up between a buy-and-hold investor and a panic-seller over real market history — then step into the Bias Arcade: eight two-minute experiments, adapted from the classic studies, that measure YOUR anchoring, loss aversion, overconfidence, and more before naming them. Play first; diagnosis after.
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Will Your Money Last? Retirement Spending
Turn the 4% rule around: your spending sets the nest egg you need, and guaranteed income shrinks it. Then stress-test the plan against real market history to see sequence-of-returns risk — whether your money survives bad luck, not just an average.
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Global Investing: Home Bias, Currency & Cycles
Own the whole world, not just home. See how small a slice your home market really is, why the lead trades between the US and international in long untimeable cycles, and when a foreign holding's currency is worth hedging — the case for owning every country in proportion.
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More tools in the workshop
- Coming soon
Value vs. Growth: The Style Cycle
Like US-vs-world, but for style: value and growth trade the lead in long cycles too. Watch the rolling gap swing, and see why the 'dead' style keeps coming back.