is leverage trading, not short selling ..or I wrong?
You can borrow coins from the exchange and sell it. Then you buy it back at a lower price.
Not for all coins. But during the dump, there is a way to earn for all coins. Sell high and buy low.
After selling
1-You can increase the total amount of coin which you sold if you believe that the price will recover.
2-You can buy the same amount of coins you sold. and you can buy another coin with the money rest.
3-You can buy a different coin which dumped harder with the expectation of relatively high recover potential.