The substack linked below only looks into one tiny sliver of the off-sheet circular financing that dwarfs even the most optimistic revenue growth, but it's a good place to start to understand why this is a bubble and that, yes, Anthropic is in fact "losing gigantic amounts of money":
"Boom and bust is not about revenue. To find that kind of risk, start by reading the balance sheet... [The 2008] bust came from off-balance-sheet instruments."
https://kennyfraser.substack.com/p/anthropic-ipo-part-one-wh...
Patrick Boyle goes into a deep dive that's well worth the watch: