Black-Scholes Explained: How Options Are Priced
The Black-Scholes options pricing model, in plain English: the formula, the five inputs, a worked example with verified numbers, and where it breaks.
Market Education
Learn how stocks, bonds and capital markets work. Explore plain-English explanations, worked examples and charts, then follow related coverage to connect market concepts with current events. Find your way around ECMSource.
Relative Strength vs RSI: What’s the Difference?
Relative Strength (RS) and the Relative Strength Index (RSI) sound alike but measure totally different things. Here’s the clean distinction.
CPI vs PCE: Why the Fed Targets PCE Inflation
CPI vs PCE explained: how the two US inflation gauges differ in scope, weights, and formula, and why the Fed’s 2% target rides on core PCE.
Credit Default Swaps Explained: How Bond Insurance Works
What is a credit default swap? How CDS premiums, credit events, and the ISDA auction work, with worked numbers and verified market data.
Options Greeks Explained: Delta, Gamma, Theta, Vega, Rho
A plain-English guide to the five option Greeks — Delta, Gamma, Theta, Vega and Rho — with worked examples, charts and common mistakes traders make.
Bond Convexity Explained: Why Duration Isn’t Enough
Duration is a tangent line; convexity is the curvature. Here is the formula, a worked 10-year Treasury example, and why MBS has negative convexity.
Investment Grade vs High Yield Bonds: A Complete Guide
How investment grade and high yield bonds differ: rating cutoffs, spreads, default rates, recovery rates, and the math behind credit risk.
Mortgage-Backed Securities Explained: Pass-Throughs & CMOs
How an MBS actually works: who issues it, how cash flows from borrower to investor, why CMOs exist, and the prepayment risk every investor must understand.
The Rule of 40 Explained: How SaaS Stocks Are Valued
How the Rule of 40 actually works: the formula, a worked example using Snowflake’s Q1 FY27, common pitfalls, and the newer Rule of X.
Margin and Margin Calls: How Borrowing to Buy Stocks Works
How buying on margin works: Reg T’s 50% rule, FINRA’s 25% maintenance minimum, what triggers a margin call, and why brokers can liquidate without notice.