This is typically measured by comparing an investment's performance against its most relevant index. (mindfullyinvesting.com)
To accomplish this, (1) the Navigation Document [ContentDocs301] must include a nav element which has the epub: type attribute value of index - term - categories, and which contains a complete list of relevant index terms; and (2) the cross-reference in the index must have an epub: type attribute value index - term - category and an href attribute value pointing to that list. (idpf.org)
The SPIVA scorecard published in mid-2017 indicated that the following percentages of stock fund managers under performed the most relevant indices over the last 5 years: (mindfullyinvesting.com)