Although long term trading of bitcoin is always preferred over short term trading but in case of altcoins it is better to do short term trading, because altcoins are highly volatile and you never know when it will going to dump.
Holding altcoins is simply waste of time according to me. We cannot assure that this coin will increase in future and we cannot able to confirm that this coin will be long last in the price chart. For traders or holders bitcoin is the best option for the investors who expect good profit in future.
Don't short your bitcoin try increase amount you hold in bitcoin and exchange it for fiat too. That will cost more.