However, until now, it has been my understanding that the way any large company works is by using their stock value as collateral against short term investments from banks, which then serve as operational funds.
You might have seen that in the crypto space, but no normal bank is going to work like that: the only point at which collateral becomes relevant is if the debtor can't pay the loan back, i.e. they're bankrupt, in which case the equity is worthless. Corporate loans will be either unsecured (companies have lots of unsecured short term debt: every single invoice sitting unpaid in accounts payable is a debt!) or secured on something physical in the way that car loans and mortgages are.
You occasionally get debt-to-equity swaps in near-bankruptcy situations.
There was a certain amount of "borrow against funds held in Ireland to avoid US repatriation taxes" done by Apple, but that wasn't using stock as security, that was using cash of a different subsidiary.
However, until now, it has been my understanding that the way any large company works is by using their stock value as collateral against short term investments from banks, which then serve as operational funds.
Am I wrong?