Oldest rule in the trading book. Problem is knowing when the floor is already hit and readying for the bounce.
Today's gains seem to be going steady with all coins gaining values. Maybe after CNY we will see spike in the BTC and ETH volumes and value again.
Yeah, it may seem too easy to just buy when its red, but the real question is until when are you going to wait or are you going to buy immediately when a currency is down? With bitcoin and ethereum, there's a bigger percentage that it will rise, but with other altcoins, not really sure.