I have read and heard that one can earn and make good money with trading bitcoins.I also want to give it a shot.Everyone says the basic rule of trading is buy low and sell high but I am confused because which ever exchange I try,the buy rate is always higher than sell rate.How can one profit if sell rate is less than buy rate.If I buy at $390, the sell rate is $380
you are right,its always happen on every exchange,they always put different buy price and sell price,just like forex. but i suggest you to looking for cheapest buy price on every exchange,and then sell it on highest sell price in every exchange,and remember to buy only when bitcoin price really down,so you will not get hard to buy "buy price"