I think they are both needed in trading we need skills to trade bitcoin or altcoins and we need luck for we have get a big profit in trading so we need that both in trading industry for to make income in bitcoin.
Trading is all about timing you need skill and experience as well as luck in order to have a strong and profitable trading history. Crypto currency does not have a regulatory board to monitor the fraudulent concepts and behavior related to the pumping and dumping of coins and you have to be very careful while dealing with these sort of situation as there is a possibility to loose most of the time if you dont have a good exit strategy
that's right skills always needed because you need to predict where to place your entry knowing the game inside crypto trading luck will followed after you place good entry and exit point.