Maybe you are a bit late to invest in bitcoin, but you can still invest in altcoin and I am sure many altcoins will be potential this year. But it is not easy to find which altcoin you should buy as many altcoins will have the same chance to increase.
I would ask them to hold on to their funds a little longer and wait for a correction to invest in any coin in the market. The alts coins pumped along with the bitcoin market and i would trust investing in bitcoin even at this price because i am confident that we will reach those valuation during the next rally but that cannot be said about the altcoin market as we are not sure what all alts will cease to develop in the next 4 years.
Waiting for a while will be a good suggestion because they can prepare to buy the coin at a lower price than the price now. But unfortunately, we do not know if the price will go down or bounce up in the next hours or days. To prevent the increases, maybe we can test to buy for a small amount and see what will happen with the market. Investing in bitcoin will be the main reason for us to invest in crypto, so we can give a big portion on bitcoin while we can invest in altcoin and split it into some part for some coins.
Indeed, bitcoin is not a new project to everyone's subconscious, it was a very old project but in particular it's been fine with time without a hint of waning by its age, it is difficult to own a few bitcoin right now, so the newcomer arrived quite late than the usual expectation but at least, they still have a chance with new altcoin, sometimes they can participate in some big volatility of bitcoin which is also relatively good. Speaking of which bitcoin is the best thing to invest in, also possible but not sure from time to time
Maybe they are too busy in these 10 years, so they do not know about bitcoin. Bitcoin becomes popular on the internet because many people spread the news about bitcoin on social media, and this year, many people read much news about bitcoin. Hence, they are curious and want to join in bitcoin. But the bitcoin price already reaches a high price and makes them feel that it is too late to invest in bitcoin. If they can learn more about bitcoin, they will see that they are not too late because they can buy bitcoin at the current price or wait for more and buy at a lower price than now.