I don't agree on this one except if you are doing trades or day trading. To me, I only buy potential altcoins so I have no reason to rush buying and selling them because I only picture the endgame. And another one is that none has that ability to have the perfect timing of making successful trades,
Well this might not work for you but may be good for others to earn. The quick buy quick sell is the strategy that helps avail the short term incremental rise in the price as benefits. The real profit lies in the long term investment and in my opinion, if some one wants to make big money.
He should invest in these coins for the long term and should not expect quick profits. This in a way helps keep the portfolio for long and in the long term the gain in the worth of the portfolio you hold is the max. So better opt for the right and more rationally defined strategy.