Investing Concepts, Explained — Well Street

Investing concepts, explainedA free, plain-English library covering investing from first principles to advanced strategy — valuation, backtesting, technical and fundamental analysis, risk, and portfolio construction. Browse all 63 guides:

What Is Investing? Why Does It Matter?

What Is a Stock? What Is a Share?

What Is a Stock Exchange?

Your First Investment

Reading a Stock Quote

Market Capitalization

Understanding Dividends

The P/E Ratio Explained

Revenue, Earnings & EPS

Types of Orders

Bull vs Bear Markets

ETFs & Index Funds

Account Types for Trading

Financial Statements Deep Dive

Valuation Methods

Technical Analysis Basics

Day Trading vs Swing Trading

Introduction to Options

Sector & Industry Analysis

The Wall Street Landscape

Trading Platforms in the US & Canada

Point-in-Time Analytics

Backtesting Strategies

Portfolio Construction

Institutional Holdings Analysis

Insider Trading Signals

Algorithmic Trading

Quantitative Strategies

Portfolio-Level Backtesting

Commitment of Traders (COT)

Senate Trading Analysis

Advanced Statistical Methods

Compound Interest: The Eighth Wonder

Dollar-Cost Averaging, Explained

Why an Emergency Fund Comes First

Inflation: Why Cash Loses Value

Saving vs Investing: When to Do Which

Bonds: Lending Money for a Living

Margin and Leverage: Borrowed Money, Amplified Outcomes

REITs: Real Estate Without the Landlording

Knowing Your Risk Tolerance

Splits, Buybacks & Corporate Actions

Taxes and Investing: The Basics

Behavioral Finance: Your Brain vs Your Portfolio

Earnings Season: The Market's Report Card

IPOs, Direct Listings & SPACs

Market Indexes: S&P, Dow, and Friends

Moats: Finding Durable Competitive Advantage

How to Read a 10-K (Without Falling Asleep)

Short Selling: Profiting From Declines

Commodities: Oil, Gold, and the Real Economy

Credit Markets: What Bond Spreads Are Telling You

Currencies and FX for Equity Investors

Interest Rates: The Gravity of Asset Prices

Macro Indicators That Move Markets

A Short History of Crashes (and Recoveries)

Machine Learning in Investing: Promise vs Reality

Market Microstructure: How Trades Actually Happen

Pairs Trading and Statistical Arbitrage

Position Sizing and the Kelly Criterion

Risk Parity and Portfolio Weighting Schemes

Volatility: Measuring and Trading Fear

Looking for a specific term? The financial glossary defines every metric in plain English.