Methodology
Every number on this site is a historical calculation. Here is exactly how each one is made — and where each one is limited.
Data source
Daily closing prices come from Yahoo Finance historical market data, retrieved for the full available history of each ticker. For the period before exchange pricing existed for Bitcoin (2010–2014) and Ethereum (2015–2017), daily prices come from the Coin Metrics community dataset, a widely used public archive of early crypto prices.
Adjustment convention
Returns are computed on adjusted closing prices. Adjustments account for stock splits and for reinvested dividends, so the figures represent total return — the same convention used by major brokerages when they show "your position, dividends reinvested". Indices (S&P 500, Dow, Nasdaq) are price indexes: index dividends are not included in the index values themselves, which slightly understates index returns versus a dividend-reinvested index fund. Crypto assets pay no dividends.
Time resolution
All tables and year scenarios use month-end closes: a scenario "in year Y" invests at the December Y−1 month-end close and values the position at the most recent month-end close. The interactive calculator uses exact trading-day closes wherever full daily history is available for the ticker; where it is not, dates resolve to the nearest month-end close and the page states this explicitly.
Dollar-cost averaging
A monthly contribution of $X adds $X at every month-end close between the start and end dates, buying fractional shares at that close. Contributions are counted in full toward the invested total.
Benchmark comparisons
"Beat the S&P 500" comparisons invest $1,000 in the ticker and $1,000 in the S&P 500 index over the same span, both at month-end closes, and compare total returns. The index is the price index; as noted above, this slightly understates a dividend-reinvested index fund.
Limits
- No taxes, trading fees, or spreads are modeled. Real accounts would keep less.
- Month-end resolution cannot capture intra-month extremes in tables.
- Early crypto prices (2010–2014) come from a different source than modern prices and were far less liquid; treat those figures as best-available estimates.
- Historical prices are facts. Future prices are not implied by them.
Attribution
Yahoo Finance historical data © Yahoo. Coin Metrics community data © Coin Metrics. This site is not affiliated with, or endorsed by, either provider. Data refreshes periodically; each page states its as-of date.