@samupaha yes it is the same as Bitcoin, and Bitcoin can't survive without buyers either as long as miners and existing owners want to cash out. It isn't just a question of market cap going down, it flat out won't survive at all if no one want to buy it. Of course in practice the price finds an equilibrium. With few buyers spending little money that equilibrium ends up being low.

@jasonmcz the net cash outs have to be equal to the net buy ins (for every seller there is a buyer). It isn't that one being larger than the other makes the price go down, it is that the price moves to the point where the two become equal. In part this happens because some people have a fixed budget they are willing to invest. If someone is going to invest $1000 that absorbs a lot more STEEM at $1/STEEM than at $5/STEEM.