When he alerts you, he already has his bags full. When his group starts buying, the price will obv rise. And guess who'll be the one you're buying your coins from?
Ohk, now I finally get it... It means in some ways, he cheats everyone just by creating some hype saying that he will pump something, whilst he already had bought and bagged 'em in and is ready to dump on everyone, right?
Sounds like it what a horrible little man if it's true taking a fee then dumping shitcoins on them!