What is a bank beaver?

Excuse me, but could you possibly clarify what you mean by "bank beaver"? As someone with expertise in the realm of cryptocurrency and finance, I'm not familiar with this specific term. Are you perhaps referring to a misspelled or colloquial term related to banking or finance that I'm unaware of? Or is it perhaps a term related to wildlife or some other unrelated field? Without further context, it's difficult for me to provide an accurate description or answer to your question. Could you please elaborate or provide some additional information?