Is it possible to rationally manipulate and speculate using bitcoin or do you have to be a believer? Two year Bitcoin volume when measured in BTC seems relati

Is it possible to rationally manipulate and speculate using bitcoin or do you have to be a believer? Two year Bitcoin volume when measured in BTC seems relatively stable while the price goes up and up and new speculators come in. As long as the price goes up the same pace as demand, there is no upper limit to the price level that steady supply of bitcoin can support. At the same time the market gets thinner and thinner relative to the bitcoin wealth. At some point the social mania around bitcoin peaks and speculators want to liquidate more than there is buyers.