There's a risk of confusing pump-and-dump which is really a form of fraud from legitimately investing in and selling something you believe in.

A scammer perpetrating a pump-and-dump go in knowing that they are only in it to raise the price and sell. Often the scammers choose projects that are otherwise dead (so that they can get in ultra-cheap). Scammers also advertise to the whole world about the investment trying to drum up others to drive up the price. Additionally, pump & dumpers are in it for the least amount of time possible. They won't want to be invested for more than a few days to a month.

Someone who is legit invests in a project because they see value in it. They believe it will go up even if they don't invest. They don't need to tell everyone about their investment (though they may choose to), and they may not even have a clear exit strategy for their investment. They may choose to hold on for years. When they do sell off the investment it's often because they no longer see as much value in the project or don't expect any more growth (or just need the money for a different purpose/project).

But there really is a clear difference in the motives of a pump & dumper and an investor.