Frequently Asked Questions
These answers cover how the Stock Investment Simulator works, where its data comes from, and what the rest of the site offers. For a visual walk-through of each mode, see the Help page.
Is this a predictor of future stock returns?
No. The simulator uses historical monthly data only and shows what happened in the past for the period you select. It does not project, forecast, or recommend a future return for any asset.
What are the three modes?
- Single — test one stock or index with a one-time deposit and/or monthly contributions.
- Compare — plot up to five tickers side by side by their actual dollar value.
- Portfolio — build a weighted basket of up to five tickers, with optional monthly rebalancing, shown against an S&P 500 benchmark.
Where does the price data come from?
All monthly closing prices originate from Yahoo Finance. They are collected into a database and served to the site through a small, read-only price API — so the simulator loads its numbers from our database rather than from files in the page. US single stocks are split-adjusted; the S&P 500 uses the raw monthly close. The available assets are US-listed stocks, ETFs, the S&P 500, and Bitcoin.
How often is the data updated?
Prices are refreshed after each month closes, using the first trading day's monthly close. The most recent update is noted in the project documentation; the latest data currently runs through mid-2026.
Does the simulator buy fractional shares?
Yes. Contributions are 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, not a precise after-tax projection. For dividend-paying stocks in particular, real total return would be somewhat higher than the price-only chart shows.
Do you recommend any particular stock?
No. This site provides an educational calculator and supporting content, not personalized investment recommendations. The choice of which tickers to include reflects reader interest in well-known US names, not an endorsement of any of them.
What are the Analysis and News sections?
The Analysis section is a small, plain-English research library organized into four tracks — Market Trend, Deep Dives, Breaking, and Basics — with each post tied to a scenario you can replay in the simulator. The News section shows broad market headlines only (not single-stock noise) for context. Neither is investment advice.
Can I trust the historical numbers?
The numbers reflect what Yahoo Finance reports. We do not adjust for delisted index constituents, reconstitution effects, or corporate actions other than splits. For high-stakes decisions, verify against primary sources or a paid market-data provider. See our Disclaimer.