Your free finance campus
Understand your money, then run the numbers
713 free guides on mortgages, debt, saving, retirement, taxes, market history and chart reading — most paired with a calculator.
Trading
Chart reading — indicators, strategies and order flow.
285Concepts
One money question each — what it means and where people go wrong.
350Settle in and read
78 in-depth articles
A separate library, at its own addresses. Each piece takes one question and follows it all the way through — including the market-history stories, from tulip mania to the 2020 crash.
Home & Mortgages
Buying, financing, and paying off a home.
9- How Much House Can You Really Afford?The income, debt, and down-payment math lenders use — and a sane rule of thumb.8 min
- 15- vs 30-Year Mortgage: Which Actually Saves More?The trade-off between a lower payment and far less lifetime interest.7 min
- How Mortgage Amortization WorksWhy your early payments are almost all interest — and when that flips.7 min
- Should You Pay Off Your Mortgage Early?What extra payments really save, and when investing beats prepaying.8 min
- What Is PMI and How Do You Get Rid of It?Private mortgage insurance, why it exists, and the 80% and 78% rules.6 min
- How Much Down Payment Do You Actually Need?The real trade-offs between 5%, 20%, and everything in between.7 min
- Renting vs Buying a Home: The Real MathBeyond “renting is throwing money away” — the full cost of each.9 min
- Is Refinancing Worth It? The Break-Even RuleHow to weigh closing costs against a lower monthly payment.7 min
- Do Biweekly Mortgage Payments Really Work?The quiet 13th payment that shaves years off a loan.6 min
Loans & Debt
Borrowing wisely and getting out of debt.
9- APR vs Interest Rate: What's the Difference?Why the two numbers differ and which one really matters.6 min
- How to Pay Off a Loan FasterWhere extra payments go, and how much interest they save.6 min
- New vs Used Car Loans and the Depreciation TrapWhy a new car can cost far more than the sticker and the interest.7 min
- Upside-Down on Your Car Loan? Here's What to DoNegative equity, how you get there, and how to climb out.6 min
- Leasing vs Buying a Car: Which Is Cheaper?Money factor, residual value, and the long game of ownership.8 min
- How to Compare Two Loan OffersPayment, total cost, and the traps hiding in a longer term.6 min
- Debt Snowball vs Avalanche: Which Should You Use?The math-optimal method versus the one you'll actually finish.7 min
- What Debt-to-Income Ratio Do Lenders Want?Front-end and back-end DTI, and the numbers that unlock approval.6 min
- Smart Ways to Pay Off Student LoansExtra payments, refinancing trade-offs, and avoiding the interest drag.7 min
Credit Cards
Interest, rewards, and using credit well.
5- The Credit Card Minimum Payment Trap, ExplainedHow a “manageable” minimum can turn a small balance into decades of debt.7 min
- How Credit Card Interest Is Actually CalculatedDaily periodic rates, the average daily balance, and the grace period.6 min
- Are 0% Balance Transfers Worth the Fee?When the promo saves you money — and when the fee eats the win.6 min
- How to Actually Maximize Cash-Back RewardsCategory multipliers, annual fees, and the interest that erases it all.6 min
- Credit Utilization: The 30% Rule and Your ScoreHow much of your limit to use, and why it moves your score fast.6 min
Saving
Emergency funds, goals, and where to keep cash.
7- How to Build an Emergency FundHow many months you really need and how to get there without pain.7 min
- High-Yield Savings vs CDs vs GICsLiquidity versus a locked-in rate, and when each one wins.7 min
- How to Save for Any Goal on a DeadlineWorking backward from a target to the monthly number that gets you there.6 min
- APY vs Interest Rate: What Your Bank Isn't Telling YouWhy the effective yield can beat the headline rate — and by how much.5 min
- How to Save for College: 529 Plans and RESPsTax-advantaged accounts and the monthly number that hits the goal.8 min
- How Long Does It Take to Save Your First $100k?Why the first $100k is the hardest — and the math that speeds it up.6 min
- The Boring Math of Becoming a MillionaireContribution rate, time, and return — the three levers that do it.7 min
Investing Basics
How growth, returns, and the markets work.
19- Compound Interest: The 8th Wonder, ExplainedWhy reinvested growth eventually dwarfs what you put in.7 min
- Dollar-Cost Averaging vs Lump-Sum InvestingWhat the research says, and why most people still average in.7 min
- What Is CAGR and Why It MattersThe single number that makes wildly different returns comparable.5 min
- The Rule of 72: Double Your Money in Your HeadA back-of-the-napkin trick for how fast money grows.4 min
- How Dividends Work (and What DRIP Does)Yield, payout, and why reinvesting quietly compounds.7 min
- How Bonds Work: Price, Yield, and MaturityWhy bond prices fall when yields rise, in plain English.8 min
- What Inflation Is Really Doing to Your MoneyThe silent tax on cash, and how to think in real dollars.6 min
- Present Value & Future Value, PlainlyWhy a dollar today beats a dollar tomorrow — and by how much.6 min
- Simple vs Compound InterestThe straight line versus the snowball, side by side.5 min
- How to Calculate Your Real (After-Inflation) ReturnThe number that tells you if you actually got richer.6 min
- How to Research a Stock: The Complete GuideCompany health, valuation, and exactly where on the internet every answer lives.28 min
- Position Sizing: The Math That Keeps Traders AliveThe 1% rule, R multiples, and expectancy — risk management the way the trading classics teach it.12 min
- Short Selling Explained: Mechanics, Costs, and RisksHow shorting actually works — borrow fees, margin calls, squeezes, and the unlimited-loss problem.11 min
- Hedging Your Portfolio: Insurance for InvestorsIndex puts, collars, futures, and beta math — what hedging costs and when it earns its keep.12 min
- Averaging Down: Smart Strategy or Falling Knife?How your average cost moves, and when adding more is a trap.6 min
- How to Measure Your Investment ReturnROI, annualized return, and CAGR — which to use when.7 min
- Index Funds vs Picking StocksWhy most active pickers lose to a boring index over time.8 min
- Crypto Profit and Cost Basis BasicsFees, cost basis, and how gains are actually measured.6 min
- Options 101: Calls, Puts, and Break-EvenThe building blocks of options and how profit is calculated at expiration.8 min
Retirement & FIRE
Building and drawing down a nest egg.
6- How Much Do You Need to Retire?The 25x rule, the 4% rule, and turning a spending number into a target.9 min
- 401(k) Match: The Free Money You Shouldn't LeaveWhy the employer match is the best return in personal finance.6 min
- Roth vs Traditional: Which Should You Pick?Pay tax now or later — and how your future rate decides it.7 min
- What Is FIRE and How Does It Work?Financial independence, the savings-rate lever, and the variants.8 min
- The 4% Rule ExplainedWhere it came from, what it assumes, and its real limits.7 min
- Coast FIRE: Let Your Savings Do the WorkSave hard early, then coast to retirement on growth alone.6 min
Market History & Stories
Famous booms, busts, and what they taught us.
12- The Dot-Com Bubble: What Happened and What It Taught InvestorsHow “eyeballs” beat earnings until the Nasdaq lost 78%.9 min
- Black Monday 1987: The Day the Market Fell 22%The largest one-day percentage crash in history, and program trading's role.7 min
- The 2008 Financial Crisis, Simply ExplainedSubprime mortgages, leverage, and how it nearly took down the system.10 min
- GameStop and the Meme-Stock Saga of 2021Short squeezes, Reddit, and the day retail traders made headlines.8 min
- The Rise of Index Funds and John Bogle's Big IdeaHow a “un-American” low-cost fund became the default way to invest.8 min
- The 2020 COVID Crash and the Fastest Recovery EverA 34% plunge in weeks, then new highs by summer — what it taught.7 min
- Bernie Madoff and the Biggest Ponzi Scheme in HistoryHow “too consistent” returns hid a $65 billion fraud for decades.8 min
- Bitcoin's Boom-and-Bust Cycles, ExplainedFour wild cycles of mania and crashes — and what drives them.8 min
- Warren Buffett's $1 Million Index-Fund BetThe ten-year wager that pitted hedge funds against a simple index.6 min
- The 1929 Crash and the Great DepressionMargin, mania, and the collapse that reshaped modern finance.9 min
- Tulip Mania: The First Famous BubbleWhen a single tulip bulb cost more than a house.6 min
- A Century of the S&P 500: What History Says About ReturnsLong-run averages, brutal drawdowns, and why time in the market matters.9 min
Income, Tax & Business
Pay, taxes, and small-business math.
5- Hourly vs Salary: How to Compare Job OffersTurning a wage into a true annual number — benefits and all.6 min
- Understanding Your Paycheck DeductionsWhere the gap between gross and take-home actually goes.6 min
- How Capital Gains Tax Works (US & Canada)Short vs long-term, the 50% inclusion rule, and what you actually owe.7 min
- Self-Employment Tax for Freelancers, ExplainedWhy 15.3% surprises new freelancers, and the deductible half.6 min
- Overtime Pay Rules, ExplainedTime-and-a-half, who qualifies, and how it's calculated.5 min
Money Basics
The everyday math behind good decisions.
6- The 50/30/20 Budget, ExplainedA dead-simple framework for splitting your take-home pay.5 min
- How to Calculate (and Grow) Your Net WorthThe single number that tracks your whole financial life.6 min
- Margin vs Markup: The Difference That Trips People UpSame profit, two very different percentages — and why it matters.5 min
- How to Find Your Break-Even PointThe units and revenue you need before you make a dime of profit.5 min
- How to Calculate a Percentage (Every Way)Percent of, percent change, and “X is what percent of Y,” once and for all.5 min
- What Is ROI and How to Calculate ItThe most-used — and most-misused — number in business.5 min