If "you sell" after the 3 or 4 mos. holding the shares. . .you then create "short term capital gains (on any profits), OR short term capital losses (in case of selling at a loss). Your brokerage house generally keeps records on this and provides you a statement in Jan. or Feb., the following year (so you can give to your tax preparer) for your annual tax return. If. . .if your brokerage does not make available these records, CONTACT THEM about these capital gains/losses!