Can anyone help me how to know if the bitcoin price will decrease?
and how to trade bitcoins and earn? 
Because i invest bitcoins in yobit.net but i didn't know how to properly trade bitcoins. Buy coin that continiusly blinking green and buy that on the lowest possible then sell on the slightly high price you can earn low profit but fast in that way and in that way you can assure that you won't buy a wrong coin and don't leave that if you want to leave sell all coin you buy to prevent losing profit