Although not completely sure, I think the top altcoins will also increase their price in 2021, so it doesn't hurt to invest in the top altcoins for today, and wait until next year. But you have to remember that investing all your money into altcoins is not recommended. If you believe the altcoins will increase in price in the next year, then just invest some of your money in the top altcoins.
As long as he can invest in the top 10-20 coin lists, he will see the coins list increase at the right time.
But do not expect that altcoin he bought will increase in the short term, although that is possible to see the altcoin will rise soon.
Maybe the trend of bitcoin rising still continues, and the altcoin needs to wait for more, but it will happen soon.
He should invest in bitcoin in a large portion as a bitcoin price can increase again anytime.