You know how this is going to end. You might be trying to lie to yourself, you might be secretly hoping that some token in your "portfolio" that you have 10 million of is going to moon to $50 and make you rich, but let's be real: that is not going to happen. Even the allegedly strong altcoins like LTC or ETH or whatever is cool these days (I've been out of this game for a while) are not doing well and BTC dominance is growing. Which makes sense if you think about it. BTC can do most of what any altcoin can do and the few really useful features that BTC is missing (private transactions for example) are implemented by multiple altcoins, fragmenting their market share.
And the elephant in the room: 99% of altcoins are total garbage. They're called shitcoins for a reason.
Sell your altcoins and tokens. Take the proceeds in BTC, stick it into a cold wallet, keep some online to play around with Lightning and other things that actually matter for real-life stuff, like being able to buy something. When was the last time you were able to use for example Ethereum for something tangible, not to buy some garbage tokens or to play a game?
Do it today. Your grandkids will thank you.
The first and most obvious is best explained with a simple phrase. Opportunity Cost. What is the next best option? That's what this opportunity is costing you. By weighing the opportunity cost, you get a good look at whether your money would make more money elsewhere. If it will, you're getting bigger gains by realizing a loss.
The second I'll cover here is much more complex and touches on tax strategies (USA, not familiar with taxes elsewhere). It's called Tax Gain/Loss Harvesting. You're in crypto, so you've had a rocking year. The year is closing out and your tax liability is looming. You can strategically realize some losses, which offsets your gains. This is complicated and should be discussed with a tax professional that is familiar with cryptocurrency trading, but realizing losses is a strategy that is used in the stock market as well.