> For the complete documentation index, see [llms.txt](https://docs.candelacharts.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.candelacharts.com/investing/risk-and-portfolio-management/period-roi.md). # Period ROI Performance over a fixed window answers a simple question: “How much are we up or down since X?” **CandelaCharts – Period ROI** makes that answer immediate by plotting the percent change between today’s daily close and the daily close from a chosen period (1M/3M/6M/1Y or custom days). It keeps the reference on a daily series so your read is consistent across chart timeframes, colors positive vs. negative regimes, and can label the latest value for quick comparisons. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.candelacharts.com/investing/risk-and-portfolio-management/period-roi.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.