Great advice. All depends on you and your risk tolerance. ETH can shoot up to 10k in a snap or Shib can make you that in the same time as well. If you already up a decent amount, take some profit, just be careful you don't kill yourself on fees. Then take some more profit on way up as it reaches higher levels. ETH gonna have staking which gives you consistent rewards so good to have some of that building up wealth.
The current ATH price doesn't matter overall. Its gonna get more momentum and keep going up. People gonna keep throwing money into ETH. They did it at 1k, 2k, 3k and now 4k. And each time the number of holders kept going up cuz they saw the potential. Look at all the people jumping on SHIB recently. They gonna keep driving up the price overtime as they want to buy in like everyone else. People not even familiar with crypto and seeing the crazy gains its made, yet BTC has been around for years. But like
@Kamala Harris said, a few hundred bucks into the big market players isn't gonna have much of an effect overall, especially for a rookie investor with not much capital. I know I wouldn't have even come near 5% of my shib gains by having put that into the big cap coins. But of course you gotta take some profits and keep yourself diversified.