Rolling returns are the returns for every period of a fixed length, such as three years, starting on each day or month across a fund's history.
A fund's 3-year return on a fact sheet is one number, measured from one start date to today. Move the start date by a few weeks and the figure can change a lot, especially if a market peak or crash sits at either end.
Rolling returns remove that luck of the dates. They take every 3-year period in, say, the last 10 years, one starting each day or each month, and work out the return for each. The result is a spread of outcomes instead of a single figure.
From that spread you can read:
For example, a fund's 3-year rolling returns over a decade might range from 2% to 25% a year, with a median of 13%, and beat its benchmark in 70% of the periods. That describes its record more fully than a single 3-year figure.
Each rolling return is a CAGR. Longer periods usually show a narrower range than shorter ones.
Each fund page has its returns, risk, costs, managers and everything it holds.