48% IRR with RPL Arbitrage: A Note Investing Case Study

The Setup

Most case studies on this site focus on the classic NPL value-add playbook: buy a non-performing loan, negotiate a modification with the borrower, then either hold for cash flow or sell the now-performing asset. The returns on that strategy are high because the investor is creating value that did not exist before.

This deal was different. Instead of buying a non-performer and fixing it, the investor purchased a re-performing loan (RPL) — a first lien where the borrower was already making consistent monthly payments — and flipped it to a passive investor at a lower yield. The profit came not from adding value, but from arbitrage: earning the spread between a higher purchase yield and a lower sale yield.

The collateral was a single-family residential property with a fair market value of $200,000. Property taxes were current, and the borrower had significant equity in the home. The unpaid principal balance (UPB) was $92,845, putting the loan-to-value ratio at just 46% — a full-equity position from every angle.

The Acquisition

The investor sourced the loan from a loan sale advisor as a one-off purchase — not part of a larger pool. The negotiated price was $61,000, which represented approximately 66% of UPB.

At that price, the monthly payment of $764 produced an annual cash-on-cash return of roughly 15%:

$764 x 12 / $61,000 = 15.03%

That alone made the deal attractive as a buy-and-hold investment. But the investor recognized an opportunity to accelerate returns by flipping the note to someone willing to accept a lower yield.

Due Diligence Highlights

The loan came with a few characteristics that made the investor comfortable with the acquisition:

• Strong payment history. The borrower had a documented track record of consistent monthly payments, and was actually paying slightly more than the required $764 each month — chipping away at principal faster than the amortization schedule required.
• Full equity coverage. With a $200,000 property and a $92,845 balance, the borrower had over $107,000 in equity at stake. That kind of skin in the game is the strongest indicator a borrower will keep paying.
• Clean first lien position. This was a senior lien, meaning no other mortgages sat ahead of it. The investor's position was fully secured by the property.
• Minor paperwork issue. There was a small documentation gap in the loan modification agreement that required the borrower to sign a clarification of intent. This was resolved without difficulty.

The Strategy: RPL Arbitrage

The arbitrage strategy in note investing works the same way it does in any market: buy at one price, sell at another, and keep the spread. What makes it possible in mortgage notes is that different investors have different return requirements.

Active investors — those who source deals, conduct due diligence, and manage workouts — typically target 15% to 30%+ returns to compensate for the time and expertise required.

Passive investors — those who want hands-off monthly income, often inside a self-directed IRA — are frequently satisfied with 10% to 15% returns. For a retirement account that might otherwise earn single digits in bonds or dividend stocks, a 12% yield on a fully secured mortgage note is compelling.

The spread between those two expectations is where the arbitrage profit lives.

In this case, the investor held the note for seven months, collecting payments and building their own seasoning with their loan servicer before listing the note for sale. That seasoning period served two purposes:

1. It demonstrated performance under the investor's ownership. A buyer can see that the borrower continued paying after the loan was transferred — not just under the prior holder.
2. It generated cash flow during the hold period. Seven months of payments at $744 net (after a $20/month servicing fee) produced $5,208 in income before the sale.

The Sale

After seven months, the investor sold the note for $73,000.

From the buyer's perspective, the math looked like this:

$764 x 12 / $73,000 = 12.57%

The buyer was purchasing at 78% of UPB and earning a 12.57% annual cash-on-cash return on a fully performing first lien secured by a property with a 46% LTV. For a passive IRA investor, that is a strong risk-adjusted return with minimal ongoing effort.

The Numbers

How the IRR Was Calculated

The ROI calculation is straightforward:

($78,208 - $61,000) / $61,000 = 28.2%

To annualize that return into an IRR, divide by the hold period expressed in years:

28.2% / (7/12) = 28.2% / 0.583 = 48.36%

The seven-month timeline is what transforms a solid 28% ROI into a headline-worthy 48% IRR. Speed matters in note investing — the faster capital is returned, the sooner it can be redeployed into the next deal, compounding returns over time.

The Buyer's Outcome

The story did not end with the sale. The buyer — a passive investor holding the note inside a self-directed IRA — went on to collect monthly payments and eventually received a full payoff when the borrower likely refinanced.

Assuming a 12-month payoff scenario (a conservative estimate, given that most borrowers historically refinance or pay off their loans within seven years):

Because the payoff occurred in exactly one year, the buyer's ROI and IRR are identical. The buyer expected 12.57% annual cash flow, but the early payoff — which included the remaining principal balance — more than doubled that return.

This is the hidden upside of buying performing notes at a discount to UPB: the monthly yield is the floor, not the ceiling. Any principal reduction event — refinance, payoff, property sale — returns the full remaining balance to the investor, producing a windfall relative to the discounted purchase price.

Both parties walked away satisfied. That is what makes arbitrage a sustainable strategy.

Why This Worked

Three factors aligned to make this RPL arbitrage deal successful:

1. The purchase yield was above the market clearing rate. Buying at 66% of UPB produced a 15% annual return — well above what most passive investors would demand. That gap between the investor's entry yield and the market's acceptable yield is the arbitrage opportunity.

2. The loan was clean and verifiable. A documented payment history, current taxes, strong equity coverage, and a first lien position all made this note easy to underwrite for the next buyer. Notes with documentation issues or unclear modification terms are harder to flip regardless of yield.

3. The investor had a buyer network. Knowing where to find passive investors — particularly those using self-directed IRAs for tax-advantaged retirement income — is what turns the theoretical spread into an actual transaction. Without a buyer, the arbitrage exists only on paper.

Arbitrage vs. Value-Add: When to Use Each

This case study sits alongside the more common NPL-to-RPL value-add strategy, and it is worth understanding when each approach makes sense.

The value-add approach generally produces higher returns because the investor is creating something — transforming a non-performer into a cash-flowing asset. Arbitrage produces more modest but more predictable returns with less effort. Many experienced note investors use both strategies within the same portfolio, depending on the deal flow available.

The Takeaway

RPL arbitrage is a viable strategy for note investors who can source re-performing loans at yields above what the broader market demands. The formula is simple: buy at a yield passive investors cannot access on their own, hold long enough to build seasoning and collect payments, then sell at a yield those investors are happy to accept.

The profit comes from three sources: the spread between purchase and sale price, the cash flow collected during the hold period, and the time value of deploying capital efficiently. In this case, all three contributed to a 48.36% IRR on a deal that required minimal active management.

For investors building their note business, arbitrage also serves a strategic purpose beyond profit. Every note sold to a passive investor is a relationship built — and those relationships lead to repeat buyers, referral business, and a reputation as a reliable source of quality assets. The $12,000 spread on this deal is meaningful, but the long-term value of a satisfied buyer network compounds far beyond any single transaction.