Terms of Use

TenYears (拾年) provides historical dollar-cost averaging simulations for USD-denominated stocks and ETFs, charts, tables, downloads, and sharing. Read these terms and the Privacy Policy before use; stop using the service if you do not accept them. Use must also comply with applicable law and the hosting platform's access requirements.

The tool does not execute trades, hold funds, connect brokerage accounts, or build or manage a real portfolio for you. Each compared asset receives the full contribution amount independently; comparisons are not an allocated portfolio.

The service is for exploring historical data and contribution calculations. It provides no personalized investment, tax, or legal advice and does not recommend buying or selling any security. Verify information independently, make your own decisions, and consult appropriately qualified professionals when needed.

Historical returns do not predict future performance. A backtest is a hypothetical simulation based on stated rules and known historical data, not an actual trading record, return guarantee, or forecast. Investments can lose value, including the entire principal.

The simulation uses daily closes from completed trading days, permits fractional shares, and rolls non-trading-day contributions to the next available close. When the current day's close is unavailable, valuation ends at the latest available trading day. Available dates and the earliest history depend on the data source.

Because the data source does not include dividend payment dates, reinvestment is modeled at the ex-dividend-date close; brokers generally execute it on the payment date. With reinvestment off, dividends are included as non-interest-bearing cash. The simulation excludes taxes, transaction fees, bid-ask spreads, slippage, currency-conversion costs, and inflation.

Prices and corporate events may be incomplete, delayed, or revised, and software may contain errors. Annualized returns use XIRR based on contribution dates; zero-principal or unavailable calculations display no rate. Read the site's methodology and compare results with independent sources before making real decisions.

Market data comes from Yahoo Finance, with dated saved datasets available as a fallback. Third-party names identify data sources or sharing destinations and do not imply their approval or endorsement of this tool. Data and service availability can change.

Fonts, hosting, market data, and social platforms have their own terms and privacy policies. Follow applicable provider requirements when visiting external platforms or reusing data. Export functionality does not grant a license to commercially redistribute market data.

You may use the export and sharing features, while retaining enough information about assets, dates, settings, sources, and assumptions to understand the result. Do not describe backtest charts as real holdings, actual trading records, or guaranteed returns, or alter attribution to mislead others.

A backtest link restores a set of parameters rather than freezing a market-data database. Results from the same link may change after data revisions. Links, QR codes, and exports contain readable investment settings. Choose your audience and confirm posts on the social platform yourself.

Sharing a link does not bypass a private site's access restrictions. Obtain any permissions needed for the content you share. The tool cannot recall copies saved, forwarded, or displayed by others on third-party platforms.

Do not use the service unlawfully, bypass access controls, disrupt the site or upstream providers, collect data in bulk without authorization, or submit inputs intended to attack systems. The operator may reasonably restrict access that causes abuse or security risks.

Site branding, content, software, and third-party market data belong to their respective rights holders. Any open-source software license is the license expressly provided in its repository. These terms do not replace third-party licenses or remove rights granted by applicable law.

The service is provided as currently available. To the extent allowed by applicable law, the operator does not guarantee complete accuracy, uninterrupted access, continuous updates, or suitability for a particular investment purpose. Maintenance, provider restrictions, or other circumstances may change or interrupt it.

You are responsible for verifying information and for your investment decisions and sharing choices. To the extent allowed by law, the operator is not responsible for investment losses arising solely from reliance on this simulation. These terms do not exclude or limit liability that cannot legally be excluded or limited, or override mandatory consumer or privacy protections.

See the Privacy Policy for data processing and browser preferences. Hosting versions may have different access controls; follow the permissions required by the version you use. Allowing language storage does not mean you agree to make investment settings public.

Read the Privacy Policy →

These terms may change with the service, and the page will show the latest update date. Material changes affecting users should receive appropriate notice and do not retroactively remove rights protected by law. Both language versions aim to express the same content. Interpret differences in context and under applicable law, without a blanket preference for a language or jurisdiction.