yes you can lose if it drops overnight.. but.. if you buy at say 0.027, sell at 0.028 you have made a profit. you come back next day and price is 0.026, you sell and then you buy at 0.025.. your still making profit. the overall downtrend is irrelivant when you operate like that as you are always making a profit over what you have sold for regardless of the fact it is going downwards in the long term.