Tools
Decision tools
Five deterministic calculators for sizing risk, comparing trade structure, combining purchase prices, projecting compound returns, and modeling option expiry payoffs. Inputs stay in this browser session.
Choose the decision to work through.
Every tool shows its units, calculation assumptions, and limitations beside the result.
Option expiry
Options profit/loss calculator
Model a single call or put at expiry, including premium, breakeven, and bounded or unlimited risk.
Open calculatorRisk budget
Position-size calculator
Find the largest tradable quantity that stays within a planned stop-loss budget before costs.
Open calculatorTrade structure
Risk/reward calculator
Compare planned price risk with potential reward and a simplified break-even rate.
Open calculatorPurchase history
DCA / average-cost calculator
Combine entered purchase lots into a weighted average purchase price before fees.
Open calculatorReturn scenario
Compound-return calculator
Project constant effective annual return assumptions with explicit contribution timing.
Open calculatorUnderstand the strategy behind the inputs.
A payoff number is useful only when you understand the position, its costs, and what can go wrong.