Now imagine if Bitcoin marketcap was 10 times higher or around $30 billion, well to move the price by $20 it would be also 10 times harder.
Not only that, currently most of the bitcoins are with day traders they won't allow prices to stabilize otherwise their profits will go away.
Well that too, since the market is so small and easy to move, Bitcoin is pretty much a safe haven for speculators. They know exactly what to do and how to move the market in order to maximize their profits.
However, looking at the Ethereum pump at the moment, it seems that all of the speculators at the moment are in the ETH/BTC market.
Only experts can make more money from this day trading not the new users. So one should be careful about the trading.