Probity allows investors to extend fully-collateralized credit to borrowers. Debt issuers post collateral in order to obtain credit from a shared credit facility. As borrowers approach the credit limit, which is limited only by the size of the fund, the algorithmic interest rate increases. The rate increases exponentially so as to create low rates under periods of high liquidity and raised rates when liquidity becomes unavailable. The platform supports a variety of tunable configurations for jurisdictional compliance with lending laws.