yes. Altcoins have often been profitable, but these depend on how legit the coin you invested is and how it is in the market. Again, Altcoins investment doesn't need a long-term investment; it's just for a short period of time, and this is because of the high risk that it has. Sometimes the coin may not be in the market anymore, so anybody who invested a huge amount of money later loses all the invested money. However, you are right by saying they DYOR. It is very important and normally not good to advise anyone when to invest or when to sell. As an investor, they need to be aware of it before they put their money in crypto.