---
title: "Return windows"
description: "Return windows are the four fixed periods Fincanva reports a return over — 1M, 1Y, YTD and MTD — two trailing from the last bar, two anchored to the calendar."
canonical_url: "https://fincanva.com/docs/analysis/return-windows"
last_updated: "2026-09-17"
md_url: "https://fincanva.com/docs/analysis/return-windows.md"
---

# Return windows

Return windows are the four fixed periods Fincanva reports a return over: **1M**, **1Y**, **YTD** and **MTD**. Two of them are trailing — 1M and 1Y count back one month and one year from the end of the data — and two are calendar-anchored, since MTD starts at the beginning of the month the data ends in and YTD at the beginning of that year. They appear as columns on the strategies list and on screener results, which is why the same strategy can show four different return figures side by side.

**Also seen as:** trailing return, rolling return, month to date, year to date

## What does each return window cover?

Each window has a fixed start rule and the same end point: the last bar of the data. The start rules below are the ones a **strategy's** windows follow. The screener's per-symbol columns carry the same four names but are anchored differently — see [do the screener's columns work the same way?](#do-the-screeners-columns-work-the-same-way) below.

| Window | Starts | The app's own description |
|---|---|---|
| 1M | one month back from the last bar (trailing) | "Return over the last month." |
| 1Y | one year back from the last bar (trailing) | "Return over the last 12 months." |
| MTD | the first day of the calendar month the last bar falls in | "Return since the start of the month." |
| YTD | the first day of the calendar year the last bar falls in | "Return since the start of the year." |

In words: 1M and 1Y answer "how did this do over the last month / last year", regardless of where those periods fall on the calendar. MTD and YTD answer "how has this done so far this month / this year", so they get longer the further into the month or year the data runs, and start over when a new one begins.

If you have seen the trailing windows written as **M1** and **Y1**, those are older labels that have been retired: **1M** and **1Y** are the names the product uses everywhere today, for the same two windows.

## Are the windows trailing or calendar-anchored?

1M and 1Y are trailing; MTD and YTD are calendar-anchored. On a strategy, a trailing window is built by rolling back one month or one year from the last bar of its data and then snapping forward to the first available price bar on or after that date — so a 1M figure covers approximately, not exactly, one month, because markets are closed on some days. A calendar-anchored window ignores the length of the period entirely and simply starts at the first day of the month or year that the last bar falls in, which makes MTD and YTD partial periods of whatever length the calendar happens to give them. All four end at the same point.

## Do the screener's columns work the same way?

No — and this is the one place the four names mislead. A strategy's windows end at **the last bar of that strategy's run**; the screener's per-symbol columns of the same names end at **today**, because they describe an instrument's own live price history rather than a stored backtest. Two figures labelled "YTD" side by side can therefore cover two different periods.

- The screener's **YTD** runs from **1 January of the current year** to today.
- The screener's **MTD** runs from the **first day of the current month** to today.
- The screener's **1Y** is the trailing twelve months up to today, drawn as the sparkline beside the return.

Those are fixed calendar anchors: they ignore the trading calendar and simply take the price on or before the anchor date. That is a different convention from a strategy's trailing windows, which roll back from the run's last bar and then snap forward to the first available price bar. **Do not read a screener column and a strategy column as the same measurement** — they answer the same question about two different things, over two periods that only coincide by accident.

## Why can a window end before today?

Because the windows end at the last bar of the data, not on today's date. For a strategy, that last bar is the final day of its [backtest](/docs/getting-started/backtest) — so a strategy that was last run a week ago shows an MTD that stops a week ago, and its four window figures do not move until the strategy is run again. "YTD" therefore means year-to-date-of-the-data, and comparing two strategies whose runs ended on different dates compares two slightly different windows.

## Defaults in Fincanva

- The strategies list shows all four as sortable columns, in the order "MTD", "1M", "YTD", "1Y", as percentages to one decimal place and coloured by sign.
- On screener results, the **Returns** tab shows "YTD", "1M" and "MTD" as numeric columns and "1Y" as a mini line chart with the return percentage beside it; each header carries the hover description quoted in the table above.
- The windows are period returns, not annualized figures: 1M is one month's return as it stands, never scaled up to a yearly rate. See [annualization](/docs/analysis/annualization) for the figures that are scaled.
- The [live book](/docs/getting-started/live-book) summary strip uses the same four windows as a selector: pick **MTD**, **YTD**, **1Y** or **1M** and every panel recomputes against that window.

## Worked example

A strategy's backtest ends on 18 March. On that run, MTD covers 1 March to 18 March. 1M is trailing, so it rolls back one calendar month to 18 February, takes the first price bar on or after that date, and runs to 18 March. YTD covers 1 January to 18 March. 1Y is trailing over the same rule, from mid-March a year earlier to 18 March. Open the same strategy in April without re-running it and none of the four figures change — they still end on 18 March, and MTD still covers 1–18 March rather than the days of April, because every window is anchored to the run's last bar rather than to today's date.

*Return windows describe what a strategy would have done on historical data, not what it will do. Fincanva provides no financial advice — see [Is this financial advice?](/docs/investing-theory/is-this-financial-advice).*