Um I don't have any other coins but in general every coin I have ever researched has had pump and dump cycles, it is really easy for a whale to come along after hearing about yenten and buy up all the yenten supply for relatively cheap then turn around and dump it all when he feels it has plateaued.

When someone owns coins it is only a matter of time before they want to sell and if he sells even 10% of his coins right now it would wipe out every buy order over 200 satoshi.  So what I'm warning about is that risk.  I am especially worried if he is a newcomer, the block explorer doesn't show past a week back so if someone wants to investigate further it would be appreciated.