Stock backtesting helps you check whether a recurring idea actually appeared across many years instead of relying on a single chart or recent memory.
Use a stock, ETF or index and avoid changing the target after seeing the result.
Choose a precise recurring entry and exit window before evaluating performance.
Consistency matters more than a single impressive average.
A strategy with a strong average return may still be fragile if most of the gain came from one or two extreme years. Looking at the distribution of outcomes helps distinguish recurring behavior from a lucky sample.
Win rate, median return and the number of observations should be considered together.
Compare 10-, 15- and 25-year samples where data allows. If the result disappears whenever the lookback changes slightly, the apparent edge may be unstable.
This does not guarantee future performance, but it is a better robustness check than optimizing one historical sample.
| Metric | Question it answers |
|---|---|
| Win rate | How often was the period positive? |
| Average return | What was the mean historical outcome? |
| Median return | What did a more typical year look like? |
| Worst year | How bad did the window get historically? |
| Sample size | How many yearly observations support the result? |
Enter a ticker in the free dashboard and test a recurring historical window.