I think the best time to buy is when the market is down and the best time to sell when the market is up.
Yes your answer very nice.I think trading is very risk.Many time we seen that coin price 1k% increase.you looks coinmarketcap all altcoin down.So its best time altcoin buy and market increase in best time sell.I think if you some altcoin buy and some month hold.You will get of huge money.