I would say that they are very susceptible to many factors. And this allows its price to be manipulated.
In every market, it's believed that manipulations do happen and that's inevitable.
When a market has got a lot of rich participations from whales and financial institutions, it's prone to manipulation. But with that said, they can have big or little impact given the situation.
And the main medium that they use for are the news that are scaring or giving good vibes.