"My two cents" (2¢) and its longer version "put my two cents in" is an American idiomatic expression, taken from the original English idiom expression: to put in "my two pennies worth" or "my tuppence worth." It is used to preface the tentative stating of one’s opinion. By deprecating the opinion to follow — suggesting its value is only two cents, a very small amount — the user of the phrase hopes to lessen the impact of a possibly contentious statement, showing politeness and humility. However, it is also sometimes used with irony when expressing a strongly felt opinion. The phrase is also used out of habit to preface uncontentious opinions. For example:
"If I may put my two cents in, that hat doesn't do you any favours." (More polite way of saying, for example: That hat is ugly.) An example of the shortened version: "My two cents is that you should sell that stock now."
