What If You Hadn't Sold That Stock
Past Investment Opportunity Cost Simulation
Investment Simulation Input
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Results
If you had invested
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FAQ
How does the missed investment opportunity cost calculator work?
It uses compound interest: amount × (1 + annual return)^years. For example, ₩10M invested at 10.5%/yr (S&P 500 average) for 10 years grows to about ₩27.14M.
Are the annual return rates accurate?
S&P 500 (10.5%), KOSPI (7.0%), and savings (2.5%) are 2005–2025 averages. Bitcoin (80%) is the 2015–2025 average including extreme early growth, so it is purely for reference. Past returns do not guarantee future results.
Is an 80% annual return for Bitcoin realistic?
Bitcoin's early surge inflates its long-run average dramatically. In some years it dropped over 70%. This figure is meant for fun, viral simulation — please do not treat it as a serious investment forecast.
What is opportunity cost?
Opportunity cost is the potential gain you forgo when choosing not to take an action. This calculator visualizes the opportunity cost of not investing in the past.
Are fees and taxes included?
No. This calculator shows simple compound returns only. Trading commissions, capital gains tax, and dividend taxes are not factored in, so real after-tax returns would be somewhat lower.
Why is the gap between savings and stock returns so large?
Compounding amplifies small rate differences enormously. A 2.5% vs 10.5% difference may look small, but over 20 years savings grows 1.64× while S&P 500 grows 7.37× — about 4.5× more.
Can I share the results with someone?
Yes. Results are saved in the URL query string, so sharing the link lets anyone see the exact same inputs and results instantly.