Frequently Asked Questions
These answers cover the most common questions about how the Stock Investment Simulator calculates results, what it models, and what it deliberately leaves out. For a longer walk-through, see the How It Works page.
Is this a predictor of future stock returns?
No. The calculator uses historical monthly data only. It shows what happened in the past for the selected period. It does not project, forecast, or recommend a future return for any asset.
Does the simulator buy fractional shares?
Yes. Contributions are modeled as if they can be allocated proportionally at each monthly close, so the tool can estimate accumulated shares and ending value cleanly. Real-world fractional-share availability depends on your broker.
Why can my real-world result be different?
Real investing includes taxes, dividends, trading fees, bid/ask spreads, execution timing, and account-specific rules that are outside this baseline model. Treat the simulator as a directional learning aid rather than a precise after-tax projection.
Do you recommend any particular stock?
No. This site provides an educational calculator and supporting content, not personalized investment recommendations. The choice of which stocks to include in the dataset reflects reader interest in well-known US and Korean tickers, not an endorsement of any of them.
Where does the price data come from?
All monthly closing prices are pulled from Yahoo Finance via the yfinance Python package. US stock data is split-adjusted; index and Korean equity data is the raw monthly close. The exact symbols are documented in the project's CLAUDE.md notes.
How often is the dataset updated?
One row per asset is appended at the start of each month, using the first trading day's close. Korean assets occasionally use the second trading day when the first is a public holiday.
Can I trust the historical numbers shown by the simulator?
The numbers reflect what Yahoo Finance reports. We do not adjust for delisted constituents, reconstitution effects in the index, or corporate actions other than splits. For high-stakes decisions, verify against primary sources or a paid market data provider.