A rumour is defined by Dictionary.com as “A story or statement in general circulation without confirmation or certainty as to facts.” Therefore a rumour is a non factual story that is circulated around.
A fact is defined by Dictionary.com as “something that actually exists; reality; truth.” Therefore a fact is something that has been witnessed by more than one person.
Facts outweigh the title of rumour. Facts are when other people have seen this issue. Facts are what intelligent people believe rather than mere rumours.