How much would my options portfolio lose if implied volatility dropped across all my positions?
Set the IV Move to Test
Then log each open options position's vega, direction, and contract count.
Your Result
Set the IV move you want to test and click Start to begin logging your open options positions.
How this is calculated
Vega estimates the dollar change in an option's price for a 1 percentage-point change in implied volatility, holding the stock price, time to expiration, and the other Greeks constant.
Long option positions carry positive vega and lose value when implied volatility drops. Short option positions carry the opposite exposure and gain value when implied volatility drops. This tool nets both directions across every position you log.
One standard equity option contract represents 100 shares unless otherwise specified, so per-contract dollar vega equals vega-per-share multiplied by 100.
This isolates the vega effect only. In practice, a sharp IV move, like the drop after an earnings report, often happens alongside a price move, so your actual profit or loss will include delta, gamma, and theta effects too, not vega alone.
This tracker only exists in your browser tab for this session and resets when you close or reload the page.
Risk & liability disclaimer: This calculator produces a mathematical estimate based on the numbers you enter. It is not financial advice and does not guarantee any trading outcome. Trading involves risk of loss, and past position sizing decisions do not predict future results. Trading Habits is not a broker-dealer, registered investment adviser, or tax professional, and is not affiliated with any broker, exchange, or data provider. We do not guarantee this tool is error-free or suitable for your situation. Always verify results independently and consult a licensed professional before making any trading or financial decision. You could lose some or all of the capital you trade with.
Know Your Whole Book's IV Risk, Not Just One Position's
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