I don't really like any of them. CryptoOptimist could be used for a trading blog, and I think that is probably the best. The others aren't really English phrases, and this could create some difficulties.
MaskedCrypto.com has just dropped, and maybe that could be used for privacy discussions. BlogDuCrypto.com has 99 back links, but I didn't check to see if they were any good.
I was asking for ideas on current domains, not suggestions for new ones. I think you are missing the point behind domain names, brand-ability being my top priority. The "trading blog" idea has already been suggested 3-4 times on this thread and using "english phrases" for a new domain are a terrible idea SEO wise, good luck getting your domain within the top 10k search results.