Baby opening and closing hands

Baby is 6 months now I’ve noticed for about a month he constantly opens and closes his hands note not just when happy I’ve looked into stimming but at minute showing no other signs or an development delays context he is 6 month rolling front and back plays with toys follows with eyes makes eye contact slightly responds to name I’d say more responding to when ya talk to him sitting up with abit of aide not fully there has anyone else expieranced this? Or even stimming if it started like that? Not sure to be worried just curious at this stage?