How to make a short profit.

Day trading. You can sell you coins and buy more in short time range, but this is highest risk of losing what you have.
you see that current coin price is high.
you sell 100 coins for 0.1 cents and get 10 dollars
then (as you predicted) price drop to 0.9 and you bought more coins.
next time when this coin price will be at 0.1, you can sell for profit
and at the next step buy more coins or the same about 100 that you have and take you usd profit