"Can anyone advise a novice trader like me why this stock has moved so much and BAR and TAS have not?"
BAR has moved from about 6 cents.The two have matched each other step for step up to 18 cents.
Until today.
Somethings up IMO.I hope so anyway.
FIS have half as many shares as BAR has,but BAR have gold interests.
TAS shares have always traded under their fair value.