TL;DR:
Most subprime lenders think they are profitable because they track the wrong numbers.
The four KPIs that actually matter are charge-off rate by vintage, roll rate by loan type, cost per funded loan, and net yield after defaults.
These numbers show whether your underwriting, collections, and unit economics are really working before the damage becomes obvious.
If you cannot pull them fast, you do not really know how your subprime lending business is performing.
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The 4 Subprime KPIs
If you run payday loans, car title loans, installment loans, or line-of-credit products, there are four numbers that tell you more about the health of your business than almost anything else on your dashboard.
These are not vanity metrics. These are operator metrics.
They tell you whether underwriting is improving, whether collections is slipping, whether your cost structure makes sense, and whether your portfolio is actually producing a real return.
If you cannot pull these four numbers fast, you are not managing a lending business. You are managing a story.
1. Charge-Off Rate by Vintage
What it is:
The percentage of loans from a specific origination period that you never collect.
Why it matters:
This is how you find out whether your underwriting is getting better or worse.
Not your gut. Not your loan officer’s opinion. Not the excuse of the month.
The math.
Looking at one big portfolio-level charge-off number hides too much. Vintage analysis forces you to compare one cohort against another.
That is how you catch a bad month, a bad policy change, a bad channel, or a bad approval trend before it becomes a year-long leak.
How to calculate it:
Loans charged off from a cohort ÷ Total loans originated in that cohort × 100
Example:
You funded 200 loans in January. By June, 28 charged off.
That gives you a 14% charge-off rate for the January vintage.
Now imagine your February vintage hits 22% over the same time window.
That is not noise. That is a warning.
Something changed.
Maybe it was underwriting.
Maybe it was lead quality.
Maybe it was pricing.
Maybe it was collections follow-up.
But something broke, and vintage tracking tells you where to start looking.
2. Roll Rate by Loan Type
What it is:
The percentage of delinquent loans that move from one past-due bucket to the next.
Why it matters:
Roll rate tells you where future charge-offs are being born.
If too many loans move from 30 days past due to 60 days past due, your problems are already forming.
If too many, then move from 60 to 90; the funeral is already being scheduled.
This is one of the clearest early-warning metrics in subprime lending.
It can tell you whether collections are slipping, whether borrower quality is deteriorating, or whether one product is behaving worse than another.
It also forces you to stop treating all delinquency as one blob.
A payday product does not behave like an installment product.
A storefront borrower does not always behave like an online borrower.
That is one reason channel and model matter so much in this business.
If you want a broader look at that issue, read Online vs. Storefront Lending in 2026: Where Profits and Pitfalls Hide.
How to calculate it:
Loans that moved from one delinquency bucket to the next ÷ Total loans in the earlier bucket × 100
Example:
50 loans are 30 days past due.
Next month, 35 of them are now 60 days past due.
Your 30 to 60 roll rate is 70%.
That is a red flag.
A high and rising roll rate means your collections process is not catching problems early enough.
And the longer you wait to fix it, the fewer good options you have left.
3. Cost Per Funded Loan
What it is:
Your total operating expenses divided by the number of loans funded in the same period.
Why it matters:
This tells you the minimum economics required to make a loan worth writing.
If you do not know your cost per funded loan, you are pricing blind.
A lot of lenders focus on approvals, applications, or funded volume.
Those numbers can look great while the unit economics are garbage.
You can be winning the activity game and losing the business.
This metric forces discipline.
It makes you ask the right questions:
Are we overstaffed for our volume?
Are our marketing costs too high?
Are our branches or channels carrying their own weight?
Are we writing loans too small to cover the real cost of acquisition and servicing?
How to calculate it:
Total operating expenses ÷ Number of loans funded
Example:
Monthly expenses are $28,000.
You funded 180 loans.
Your cost per funded loan is $155.
If your average loan is $400, and your economics only produce $120 per loan before defaults, you are upside down before you count a single charge-off.
That is not a collections problem. That is a business model problem.
It is also why some lenders lose more money to caution than default.
They cut growth in the wrong places, tolerate dead costs too long, or keep writing loans that never had enough room in them to work in the first place.
For more on that, read Subprime Lenders Lose More Money to Caution Than They Ever Lose to Default.
4. Net Yield After Defaults
What it is:
Your actual return on the loan portfolio after charge-offs, cost of funds, and operating costs.
Why it matters:
This is the scoreboard.
Everything else feeds into this.
You can have strong originations, stable delinquency, and decent collections notes in the system.
None of it matters if the portfolio is not producing a real return after losses and overhead.
This is the number that tells you whether you have a business or a habit.
How to calculate it:
(Fee and interest income − Charge-offs − Cost of funds − Operating costs) ÷ Average outstanding portfolio balance × 100
Example:
You collect $45,000 in fees and interest.
Charge-offs cost $8,000.
Cost of funds is $3,000.
Operating costs are $12,000.
That leaves $22,000.
If your average portfolio balance is $300,000, your monthly net yield is 7.3%.
That annualizes to roughly 87%.
That is not just activity. That is actual performance.
If your net yield is thin, flat, or constantly getting rescued by accounting optimism, you do not have a slow month. You have a structural problem.
The Real Point
Most subprime lenders do not go broke because they lack reports.
They go broke because they watch the wrong ones.
If you track charge-off rate by vintage, roll rate by loan type, cost per funded loan, and net yield after defaults, you will see problems earlier.
You will make better decisions faster.
And you will stop confusing motion with profit.
That is the whole game.
Not looking busy.
Not sounding smart in meetings.
Not staring at a P&L that flatters you while the portfolio quietly rots underneath it.
If you want to stay in this business, you need to know how to loan money to strangers without getting your butt handed to you.
And that starts with the right scoreboard.
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FAQ
What is the most important KPI in subprime lending?
There is no single magic KPI, but net yield after defaults is the closest thing to a final scoreboard. It shows whether the portfolio is producing a real return after losses, funding costs, and operating expenses.
Why should lenders track charge-off rate by vintage?
Vintage tracking shows whether one origination period is performing better or worse than another. That helps you spot underwriting or channel problems earlier than a blended portfolio view.
What does roll rate tell a lender?
Roll rate shows how delinquent loans migrate from one past-due bucket to the next. It helps you identify collections weakness and rising credit deterioration before those loans become charge-offs.
Why does cost per funded loan matter so much?
Because it tells you whether your unit economics make sense. If the cost to acquire, fund, and service each loan is too high, volume can grow while profitability gets worse.
Who is this post for?
This post is for subprime lenders, startup operators, storefront lenders, online lenders, vendors, attorneys, consultants, and anyone trying to understand how a loan portfolio actually makes money or loses it.
What do I get from the Inner Circle newsletter?
You get Jer Ayles’ free weekly take on what to measure, what to ignore, and what is shaping the business of lending money to the masses right now.