The lab
24 simulations, from your first compound interest curve to pricing options and backtesting trading rules. Move the dials and the math responds in real time. Nothing to install, nothing to sign up for.
Money that grows and shrinks
Compounding, debt, saving and retiring: the math that decides most people's financial lives.
- Time value of moneyGrow money forward with compounding, then pull future cash back to today.Intro2 episodes
- The debt trapSee how minimum payments stretch a credit card balance over decades, then race avalanche against snowball.Intro
- Lump sum or a little each monthInvest all at once or spread it out? Replay every start date since 2005 and count which won.CoreReal market data
- Retirement and sequence riskTest the 4% rule against thousands of markets, and see why the order of returns can matter more than the average.Core
Probability and chance
Randomness, averages, beliefs and bets. The toolkit underneath every model in finance.
- Random walk to Brownian motionShrink a coin-flip walk until it becomes continuous, and watch uncertainty grow with √t.Intro1 episode
- Expected value vs your pathPlay a game that wins on average and see how often a single player still goes broke.Intro1 episode
- The central limit theoremAverage lopsided dice and watch a bell curve appear out of nowhere.Core
- Skill or luck? Bayesian updatingWatch a fund manager's record come in and update your belief, one result at a time.Core
- Gambler's ruinA small edge, a finite bankroll. Find out how likely you are to hit zero before you hit your goal.Core
- The Kelly criterionBet too little and you grow slowly. Bet too much and you go broke. Find the fraction in between.Advanced
Risk and portfolios
How returns wobble, how assets move together, and what happens in the tails.
- Volatility is not riskTwo assets, same destination, very different rides. And a calm one that quietly sinks.Intro2 episodes
- Log returnsSee why +10% then −10% doesn't get you back, and why log returns simply add up.Intro1 episode
- Volatility drag and leverageWhy a 3× fund doesn't return 3× over time, and how swings quietly eat compound growth.Core
- Correlation and covarianceDial a correlation from −1 to +1 and watch two assets move together, apart, or not at all.Intro2 episodes
- Diversification and portfolio riskMix two assets, trace the efficient frontier, then switch on a crisis and watch correlations jump.Core4 episodes
- Beta and the marketRegress a real stock against the S&P 500 to split its returns into market, alpha and noise.CoreReal market data
- Bell curves and fat tailsCompare the normal distribution with fat-tailed and skewed returns, and count the impossible days.Core3 episodes
- Volatility clusteringCalm follows calm and storms follow storms. Build a GARCH market and see it happen.Advanced
- Tail risk and black swansFeel the math of a 50% loss, then stress a portfolio that looks safe until it doesn't.Core2 episodes
- Monte Carlo labSimulate thousands of futures for a portfolio and watch the distribution of outcomes form.Core2 episodes
Markets, models and derivatives
Options, bonds and trading rules, priced and tested the way quants do it.
- Bonds, yields and durationPrice a bond, then move interest rates and see why long bonds swing the hardest.Core
- Options and Black–ScholesBuild calls, puts and spreads, price them with Black–Scholes, and watch the Greeks move.Advanced
- Mean reversion and pairs tradingSimulate a spread that snaps back to its average and trade it, until the relationship breaks.Advanced
- Backtest a trading ruleTest a moving-average rule on real prices, then see how easy it is to fool yourself by overfitting.AdvancedReal market data