The idea of buying undervalued coins in the market and sell when it gets back is a horrible idea if the cryptocurrency market is not in the blood bath season which will technically affect the price of all the coin in the market. However, the best things to do now is to invest in coins that are gaining genuine positive trend in the current bullish market.
Obviously it is not going to be a profitable venture if it is in a horrible situation, look at crypto market right now, everything has gone down so much in the past 24 hours or so. However if it is in a bullish market, that means every coin will go up, what better idea is there to buy into something undervalued on a bull crypto market?
It will be a double increase, it will both go up because it will be undervalued so it will go up as much as whatever the real value it should be, but it will also go up because there will be a bull run as well so it will go up even faster than everything else. I am not saying these coins will be like that, I do not even like them all that much, but all I am saying is I understand the idea of investing into the undervalued coins to make more money during a bull run. Maybe he is right, maybe he is wrong, only time will tell.