Always the same scheme. Pump it till 430-450 and sell... Why can´t they simply let it grow?
Because the ones buying are the ones selling (market makers), hoping to end up with more fiat than they started with.
Besides that is healthy and expected, just recently we were testing ~370$ as a bottom. It is the human brain that does not easily deal with a (paper) loss, but easily forgets about the recent gains (always wanting more).