Live · 22 Oct 2026 SPX 7,651.95 -1.36% NDX 29,000.28 -2.76% VIX 19.20 +15.11% GOLD 4,051.70 -2.37% CL 99.00 -2.74% BTC 81,094.29 -3.47%

Investment Concepts

Plain-language explainers of key financial and quantitative concepts used across the platform.

foundry-sharpe-ratio
· Foundry, Investment Concepts

What Is the Calmar Ratio — Returns Measured Against Your Worst Day

What Is the Calmar Ratio — Returns Measured Against Your Worst Day Investment Concepts What Really Matters: How Much Did You Lose? The Calmar ratio…

foundry-sharpe-ratio
· Foundry, Investment Concepts

What Is the Kelly Criterion — the Maths Behind Position Sizing

What Is the Kelly Criterion — the Maths Behind Position Sizing Investment Concepts How Much Should You Bet? Most investors obsess over what to buy.…

foundry-sharpe-ratio
· Foundry, Investment Concepts

What Is the Sharpe Ratio — Measuring Returns Against Risk

What Is the Sharpe Ratio — Measuring Returns Against Risk Investment Concepts Not All Returns Are Equal Making 20% sounds great. But what if you…

foundry-margin-safety
· Foundry, Investment Concepts

What Is Margin of Safety — Buffett’s Most Important Principle

What Is Margin of Safety — Buffett’s Most Important Principle Investment Concepts The Buffer That Saves You Margin of safety is the gap between what…

foundry-pe-ratio
· Foundry, Investment Concepts

What Is Fair Value? How to Calculate a Stock’s Worth

What Is Fair Value — and Can You Actually Calculate It? Investment Concepts The Price vs Value Question Every investor eventually asks the same question:…

foundry-roe
· Foundry, Investment Concepts

What Is Return on Equity — Measuring How Hard Your Capital Works

What Is Return on Equity — Measuring How Hard Your Capital Works Investment Concepts The Efficiency Test Return on Equity (ROE) measures how effectively a…

foundry-pe-ratio
· Foundry, Investment Concepts

What Is the P/E Ratio — and Why Every Investor Watches It

What Is the P/E Ratio — and Why Every Investor Watches It Investment Concepts The Price Tag on Earnings The Price-to-Earnings ratio — universally called…

Get our weekly market brief free.