Well, let's apply this to Bitcoin This could become helpful for people who want to sell or spend their BTC eventually.

You'd say "but there's a clear market price for Bitcoin!" and you would be correct. At a single moment, normally across exchanges there's a quite narrow price range.

However, you can apply these methods to the question in which market phase you should sell your Bitcoin.

The simplest one here again is ...

You bought your Bitcoin for a certain price. Sell them when you got a profit you're comfortable with (e.g. 50 or 100%). Miners can apply this too, taking their cost as a base and deciding when to sell and when to accumulate.

This is also a quite interesting strategy for Bitcoin. The idea is that you estimate how valuable would be Bitcoin if it eventually stabilizes. Will it replace gold? Or will it remain niche? The Total Addressable Market strategy does exactly that, it's one of the methods institutional investors use to decide when to sell.

This one instead may not apply really to Bitcoin at this moment. Bitcoin's competition is currently much weaker. It could become an issue if you fear that some altcoin is about to "flip" Bitcoin's importance, but most altcoins, including Ethereum, address different markets as they are neither decentralized nor really lack a single point of failure.

If Monero cames close to BTC however you may have to adjust your Bitcoin selling price due to "real" competition. This is extremely unlikely, but not completely impossible.