Kitson Options Payoff and Greeks Explainer: See How an Options Position Makes and Loses Money (Opus 5.5)

See exactly how an options position makes and loses money: payoff, Greeks, breakevens and what-ifs, worked out on your computer.

Type a position leg by leg on a made-up underlying, or pick one of seven examples: a long call, a covered call, a cash-secured put, a bull call spread, an iron condor, a straddle or a calendar spread. You type the price, volatility, interest rate and dividend yield yourself: the app fetches no market data.

Options Payoff and Greeks Explainer works out everything in code with the Black-Scholes-Merton model, and states every formula:

- the model price and the Greeks of each leg (delta, gamma, theta a day, vega and rho a point), and the implied volatility of each premium you typed;

- the profit or loss at expiry and today across a range of prices, as a chart;

- breakevens, maximum profit and loss (including unlimited) and the capital at risk;

- the model probability of a profit and of finishing above or below each breakeven;

- two what-if grids: price by days left, and volatility up and down;

- notes on early exercise, assignment and margin.

Claude Opus 5.5 then explains the position in plain words: what each leg does, what the Greeks mean here, where the risks are and what changes the picture, with questions to check in your broker's documents. A short quiz, marked by the app, and a Greeks glossary help it stick.

What makes it different

- The maths is done in code, not by the AI, and checked in our tests against textbook examples (Hull, Haug).

- Probabilities are model outputs, not forecasts. They come from the model's assumptions (a lognormal price, one volatility), are labelled that way everywhere, and the app asks for a rewrite if the explanation gives a percentage chance without saying it is a model value.

- Every number in the explanation is checked in code against the app's own figures, and the result of that check is shown to you.

- It never tells you to buy, sell, write, roll or close anything. If the explanation drifts into advice, forecasts or promises, the app catches it and asks for a rewrite.

- The cost is shown before every run, and you set a limit. In our own test on made-up data (an iron condor), a run cost about 18 cents on our own Anthropic account, and one change about 8 cents more. That run included one automatic rewording request caused by a false alarm in the app's wording check, since fixed; the cost has not been measured again.

- A Word report and an Excel file of the legs, Greeks, payoff table, what-if grids, notes, glossary and quiz.

What you need

- Free Node.js 18+ (Windows, Mac or Linux).

- Your own Anthropic account and API key, with a little credit. A Claude chat subscription does not include API access.

- No files and no market data: you type the position, or use the built-in examples.

You pay Anthropic directly for what you use, on top of the price of the app.

Educational only. Model values on made-up or your own inputs, not market prices. Probabilities are model outputs, not forecasts. Past or simulated results do not predict future results. Not financial advice. It explains a position and does not recommend any trade. Options can lose more than you expect, and selling options can lose more than the premium received. The app never places trades. Trading involves risk of loss. If we can't get the app running for you, email kit376351@gmail.com within 14 days for a refund of the app price. Kitson Workshop is not affiliated with or endorsed by Anthropic.