<prompt> Human: Hi PF, Im new to investing. I think this table shows that my returns for the entire year until today in VTSMX have been 14.08, but Im confused about what the 1 year performance of 8.51 means, then? Im sure this is a stupid question, sorry.EDIT: Thanks everyone - that clarifies it for me!  <response>: YDT ! 1 year. Year-to-date started January 1, 2016 and runs to December 13. The 1 year was last updated November 30. Both of those dates are written in the image you linked. 