The only reason Anthropic has cash is because VC keep giving them the money. They never had a positive quarter, with revenue always lower than expenses regardless of their growth, thus burning money from VC.

If VC money gets tight, they would have to issue debt, that pay interests. With a current negative EBITDA, their bond will be junk at IPO, paying higher interests and having a lot less market than AAA debt (e.g. Google has access to that market). Both things combined translate to "running out of cash".