Replacing the margin loan with blockchain

Hi all

Are there any projects that are working on a replacement to a margin loan with cryptocurrency? For example a borrower who can use traditional stocks as collateral for a loan in crypto which is funded by other depositers of crypto (not a bank).

I understand you can use crypto as collateral now for a crypto loan.

If there are no projects like this - would this be something thats possible with a smart contract? Or is it difficult to do given stocks are not held on a blockchain?

Thanks