Pump and dump are completely normal things when it comes to Bitcoin, it's just how it's functioning. So if you want to invest in Bitcoin this is something that you will have to accept. So far it's been.shown that on long term Bitcoin is good investment but you have to be clear with yourself what is your final goal and strategy.
Bitcoin is really good as an long term investment and if you can manage to hold your coins longer then you can expect profitable results from it as it is predicted that price will rise in long run.