Methodology

Roll comparison calculator methodology

The roll comparison isolates what changes if the trader closes the current position and opens the proposed replacement.

Core formulas

• Current P/L: debit positions use current value minus entry debit; credit positions use entry credit minus current value.
• Percent of max profit captured: current P/L divided by maximum possible profit.
• Remaining risk: maximum loss minus current P/L, floored at zero.
• Roll net: proposed roll credit is positive; proposed roll debit is negative.
• Combined basis: original credit/debit adjusted by the roll debit or credit.
• Risk-to-reward from here: remaining profit potential divided by remaining risk.

The tool does not invent missing option prices or forecast probabilities.

Primary reading: FINRA options overview · FINRA assignment guide · OIC options basics · OIC exercising options · OCC options disclosure document · SEC Investor Bulletin on options