For those who have experience investing in mortgage notes, what are the most important things you look at before purchasing a note?

I’m especially interested in how you evaluate the borrower’s payment history, property value, remaining balance, interest rate, and overall risk.

For performing and non-performing notes, are there any red flags you wish you had known about before getting started? And what due diligence steps have helped you avoid problem investments?

Would love to hear from experienced note investors about what you’ve learned along the way.