There is such a thing as "overselling".
of course there is , overselling a.k.a the dump of the coin do happens all the time .
Sometimes a token becomes so cheap that a whale can easily manipulate prices to a point where it's much more profitable to artificially pump prices.
whale's dont wait for the coin to dump in order for them to manipulate it because even expensive coins like bitcoin are also being manipulated by them at all times but i dont think that its profitable on thier side since they are the one's who buy at a large volume's .
Watch the market closely and start reading the charts - it's simpler than it looks.
simplier ? no meyt its not easy to just watch and read the charts . cant you see that even experience traders do also loose no matter how skillful they are ? that's because anything can happen on this market . there are whales and other factors that affects your trading style .