The price is dropping down recently, But Bitcoin is always profitable, because it have the most promising potential among crypto currencies, and the number of its traders around the world is really huge. So The price is going to increase again after some time, and that's the best time to buy more BTC as the price is low.
I should say that i really want to invest in bitcoin, sometimes the price is yes dropping but bitcoin is easily increasing and so that is the reason why i should really want to invest in bitcoin because you can be easily become a millionaire while investing in bitcoin, i must invest and wait patiently for the increasing of bitcoin, like other millionaires now who invest in bitcoin.