If we all start buying one single coin at the same time what will happen?

title, if we do that would we create a bull run of a coin?I'm sure that because of the bull run, other people who doesn't know this subreddit will start buying at the same time so it will be even higher and then we all start selling at the same time with proft, it is even legal?

There is a law but that's for famous people, people with high status can't go on social media telling to their followers "go buy this now" but none of the people in here are like that, if we do that is as a group not as a single famous person or something idk