Probability Calculator Help
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The Probability Calculator estimates the probability that a stock will finish above, below, or within a target range at a future date.
How to use it
- Enter the symbol and the target date.
- Set the lower / upper bounds. Either dollar prices or percentages.
- Pick a model.
- Black-Scholes (default): closed-form lognormal distribution.
- Monte Carlo: numerical simulation, useful for modelling jumps or non-standard volatility paths.
- Read the result. The calculator returns the probability of the underlying being inside, above, or below the chosen range.
Tips
- Tweak the implied volatility input to stress-test results — small changes in IV produce large changes in tail probabilities.
- The Monte Carlo mode lets you specify a custom drift and volatility for advanced scenarios.