Options Trading Guides & Glossary

Plain-English explanations of Open Interest, Put-Call Ratio, Max Pain, and option Greeks — the core concepts every Replete Alpha tool is built on.

• What Is Open Interest (OI) in Options Trading?

  Open Interest is the total number of outstanding (not yet closed) option or futures contracts for a strike and expiry. Reading how OI changes alongside price is one of the fastest ways to gauge whether new money is entering or leaving a position.

• Put-Call Ratio (PCR): What It Is and How to Read It

  Put-Call Ratio (PCR) compares total put activity to total call activity to gauge whether the options market is leaning bearish (more puts) or bullish (more calls) — and, read carefully, is often used as a contrarian sentiment indicator.

• What Is Max Pain in Options Trading?

  Max Pain is the strike price at which the total payout to option buyers, across every outstanding call and put, would be smallest at expiry — equivalently, where option writers as a group would lose the least.

• Options Greeks Explained: Delta, Gamma, Theta, Vega

  The option Greeks — Delta, Gamma, Theta, and Vega — each measure how an option's price responds to one specific change: in the underlying's price, in that sensitivity itself, in time, and in implied volatility.