Good timing. But on the other hand if you had sold AAPL, MSFT, NVDA, ORCL, AVGO, ADI, KLAC, LRCX, etc at the Internet bubble top then you would have missed out on huge gains since then.
Only if you never repurchased.
Or you could DCA out: have a standard policy that no single stock can be more that x% of your portfolio, and as any one gets above that limit you crystallize profits. It's no different than having a 60/40 portfolio and rebalancing your equities if they get >60%.
I lean more towards passive and (total) market index funds, and just riding the roller coaster, as anything else is fairly either impossible or too time consuming:
* https://ofdollarsanddata.com/even-god-couldnt-beat-dollar-co...