I want to ask where the other currencies like SOL, BNB, ETH... are valued? Which currency is used as the base for comparison.

In reality, Gold is a fixed valuation commodity, BTC is an irrationally valued commodity. It is unverified and I don't want to say that the market is deceiving people. Therefore, don't expect to get rich by investing here. This is a deception and if you buy in, your money is real but the value you receive back is illusory.

Has anyone taken profits decisively yet? I see 90% are losing and many negative posts.

So manage your capital. Don't put all your money into this. Just put in 10% and learn; even in a deception, there are times when one gets burned. Therefore, learning and managing greed is important.

Be aware of managing your own greed, don't listen to groups. Don't set expectations of x10 or x100.