If you want to purchase debt portfolios, you first need to find sellers!
Usual sellers are banks and credit companies which most probably already are in business with debt buying companies that are able to put enough cash on the table to buy large portfolios every year.
These portfolios are the residual of much larger ones that have been deeply and intensively worked on by debt collection services, third parties collection agencies, etc.
They are the “tank bottom” that is too hard to collect and this is the reason why it is sold.
Sellers perfectly know the real value of these portfolios and so do the buyers. This is why such portfolios are sold for pennies on the dollar.
Now, you must realize that almost each and every company around the world charges off debts every year.
Reasons why they did not collect those debts are: