Not familiar with prosper, but B loans are usually not high in demand, so I say not so easy to sell. The rates does not fall, it is the pennies of interest each month that goes down. Smaller principal means a smaller interest but the rate did not change.

When you get near the end of the loan (less than 12 payments)...let's say there are 6 payments left. The yield looks like it halved because there are no longer on an annual basis. APR is an annual rate, what you get in the next 12 months. If there are only 6 months of returns in the next 12 months, it looks like half the yield of the same loan with 12 months or more. So a 12% rate looks like a 6% yield when there are 6 payment left (but the rate really did not change). If you try to sell this with a 7% mark-up, LC won't let you. If you have a loan with 3 payments left, and it has a 2% yield and you attempt to sell with a 3% mark-up, it won't let you. So there are loans that I put in the "mature" bucket that you cannot apply your blanket mark-up.