Tools · Process

Thesis Invalidation Calculator

Decide what would prove you wrong before you own the position long enough to get attached to it. Pick the metric your thesis actually depends on, set the level that breaks it, and get a concrete number to watch — a price if the metric is a multiple, a print if it’s a fundamental.

Use this when your thesis is really a re-rating call — the market will keep paying X, or won't.
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A kill price only works if you actually check it. The Trading Journal Audit framework looks at whether your past exits matched your stated invalidators — or whether you moved the goalposts once the position was down.

See how the Trading Journal Audit works →

Common questions

Are these calculators investment advice?

No. They do arithmetic. AlphaLens does the research. Every decision is yours.

Do the calculators store my portfolio?

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Go deeper

How to Research a Stock → Long-Term Investment Thesis framework →

Related tools

Position Size Calculator Turn your stop and risk tolerance into a share count. Margin of Safety Calculator The valuation cushion your thesis may depend on.
All investing calculators →

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Disclaimer: NorrisAI AlphaLens tools are educational calculators only. They are not investment advice, a recommendation to buy or sell any security, or a substitute for a financial advisor. NorrisAI is not a registered investment adviser, broker-dealer, or fiduciary. Results are estimates based on the numbers you enter and the assumptions shown. Markets, taxes, fees, and company fundamentals change. You are solely responsible for your decisions.
Educational calculator only. Not investment advice. — NorrisAI AlphaLens
Calculator by NorrisAI AlphaLens

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