Learn the ideas behind every stock
Clear, practical explainers on how to read and value companies — the concepts behind each quiz question, from first principles to analyst depth.
32 articles · a guided path from first principles to analyst depth
Foundations
Start here. The vocabulary and habits every investor needs before picking a single stock.
Stock Market Basics: What a Share Really Is
Start here. What a share of stock represents, the first terms every investor meets (market cap, dividend, EPS, P/E, volatility), and the crucial difference between a stock's price and its value.
How to Buy Your First Stock: Accounts, Orders and Tickers
Buying your first share is four simple steps: open a brokerage account, fund it, find the ticker, and place an order. Learn the difference between market and limit orders, what a ticker is, and the beginner mistakes to avoid.
How Stock Exchanges Work
Where shares actually change hands. What an exchange is, how a buyer and a seller get matched, and what the bid, the ask and the spread really mean.
The Power of Compounding: How to Start Investing for the Long Run
Compounding is earning returns on your returns, and it rewards patience more than cleverness. Learn how it snowballs over time, why starting early matters, and two simple beginner habits — investing regularly and staying invested — that put it to work.
Bull and Bear Markets: Reading Market Cycles
Markets move in long swings of optimism and fear. What bull and bear markets are, why corrections are normal, and why time in the market usually beats timing the market.
ETFs and Index Funds: One Purchase, Hundreds of Stocks
Index funds and ETFs let you own hundreds of companies in a single, low-cost investment. Learn how they work, the difference between passive and active, what an expense ratio is, and why they're the classic beginner choice.
Analyzing Stocks
How to read a company and judge what it's worth — profitability, cash flow, valuation and risk.
Dividends Explained: Yield, Payout Ratio and Sustainability
A dividend is only as safe as the earnings behind it. Understand dividend yield, the payout ratio, dividend growth, the dreaded yield trap, and the trade-off between yield and growth.
How to Read an Income Statement
The income statement shows whether a company actually makes money. Walk from revenue down to net profit, and learn what gross, operating and net margins each reveal.
How to Read a Balance Sheet: Assets, Liabilities and Equity
The balance sheet shows what a company owns, owes and is worth on paper. Learn the simple assets = liabilities + equity equation, what working capital is, and the safety checks (current ratio, debt-to-equity, net debt/EBITDA) that flag financial strain.
The P/E Ratio: What It Really Tells You
The price-to-earnings ratio is the most quoted and most misused number in investing. Learn what P/E measures, trailing vs. forward, why a low P/E isn't automatically cheap, and how to compare it fairly.
Free Cash Flow: The Cash a Business Actually Keeps
Profit is an opinion; cash is a fact. Learn what free cash flow (FCF) is, how it differs from accounting profit, the P/FCF and FCF-margin checks, and why many investors trust cash flow more than earnings.
How to Value a Stock: Multiples, DCF and Margin of Safety
Is a stock cheap or expensive? Learn the main valuation tools — P/E, P/S, P/B and EV/EBITDA multiples, discounted cash flow, and the margin-of-safety mindset — and how to use them together.
Understanding Profitability: Margins and Returns on Capital
Profitability ratios separate genuinely good businesses from merely big ones. Understand gross, operating and net margins, and the returns-on-capital trio — ROE, ROA and ROIC.
Price-to-Book and Asset Value
The price-to-book ratio compares a company's market price to the value of its net assets. Learn what book value is, when P/B is useful, and where it badly misleads.
Investment Risk Explained: Business Risk, Volatility and the Balance Sheet
Risk is more than a falling price. Learn the difference between business risk and market risk, the balance-sheet metrics that flag danger (debt/equity, interest coverage, current ratio), and why diversification helps.
Enterprise Value and EV Multiples: Valuing the Whole Business
Market cap prices the shares; enterprise value prices the whole business, debt included. Learn what EV is, how EV/EBITDA, EV/EBIT and EV/Sales work, and why they beat the P/E ratio for comparing companies with different debt.
Growth Investing Basics: Finding Durable, Profitable Growth
Growth investing bets on faster-than-average expansion. Learn what to measure (revenue, earnings and FCF growth, reinvestment × ROIC, the addressable market), how to tell quality growth from growth at any cost, and why the price you pay still matters.
ROIC vs ROE vs ROI: The Complete Guide to the Three Return Metrics
ROI, ROE and ROIC all measure return on money, but each uses a different definition of “money in”. This guide explains the difference with worked examples — in beginner, intermediate and advanced versions — and shows why ROIC, not ROE, is the metric most tied to long-term value creation.
Insider and Market Signals: Reading Who's Buying and What Analysts Expect
Insider trades, institutional flows and analyst expectations can hint at information the financials haven't shown yet. Learn to read these signals as supporting clues — never as standalone proof.
Portfolio & Strategy
Putting it together: choosing a style, spreading risk, and understanding the forces that move markets.
Value vs Growth vs Income: Choosing an Investing Style
Value, growth and income are the three classic investing styles. Learn what each one looks for, the metrics that matter to each, their trade-offs, and why picking a style you can stick with matters more than picking the 'best' one.
Dollar-Cost Averaging
Investing a fixed amount on a regular schedule, regardless of price. Why this simple habit lowers timing risk, smooths your average cost, and keeps emotion out of investing.
Diversification and Asset Allocation: The Only Free Lunch
Diversification spreads risk across many holdings; asset allocation decides your split between stocks, bonds and cash. Learn why combining uncorrelated assets lowers risk without sacrificing much return, and how to think about your mix.
Rebalancing Your Portfolio
Over time, winners grow to dominate a portfolio and quietly raise its risk. Rebalancing trims them back to your target mix — selling high and buying low by design.
Behavioral Finance: Avoiding Your Own Worst Enemy
Most investing mistakes are psychological, not analytical. Learn the biases that cost investors money — loss aversion, herding, confirmation bias, anchoring and overconfidence — and the simple guardrails that keep you disciplined.
Inflation, Interest Rates and the Economy: The Forces Behind the Market
Inflation and interest rates are the macro forces that move every market. Learn how central banks use rates to fight inflation, why higher rates tend to lower stock prices (especially growth stocks), and what it means for your portfolio.
Options
Beyond shares — how options contracts work, what drives their price, and the core strategies.
Options Explained: Calls, Puts, Strikes and Expiration
An option is a contract, not a share. Learn the four building blocks every option shares — call vs. put, strike price, expiration and premium — and what it means to be the buyer versus the writer.
Moneyness: In, At and Out of the Money
Moneyness describes where the stock price sits relative to the strike. Learn ITM, ATM and OTM for calls and puts, and how every premium splits into intrinsic value and time value.
Options Expiration and Assignment
Every option has a deadline. Learn what happens at expiration, the difference between exercise and assignment, and why time decay works against option buyers every day.
Covered Calls for Income
Selling call options against stock you already own to collect premium income. How the covered call works, the income-for-upside trade-off, and the risks to weigh.
Basic Options Strategies: Covered Calls, Protective Puts and Spreads
You don't have to buy a bare call to use options. Learn the four foundational strategies — covered call, protective put, and the two vertical spreads — and the risk each one is built to shape.
The Option Greeks: Delta, Gamma, Theta and Vega
The Greeks measure how an option's price reacts to the things that move it: the stock, the passage of time and volatility. Learn delta, gamma, theta, vega and rho and what each one warns you about.
Implied Volatility and What Drives an Option's Price
Two options on the same stock can cost wildly different amounts. Learn how implied volatility, time to expiry and moneyness set an option's premium — and why IV is the part traders argue about.
