Unitranche Loans Explained: The Dominant Deal Structure in Private Credit

One loan, one rate, no layers to argue over: unitranche won private credit on speed and simplicity. That blended rate also hides exactly where the losses land when a deal goes wrong.

Key takeaways

• A unitranche merges senior and junior debt into one credit agreement with a single blended rate; the risk split lives in a private Agreement Among Lenders as a first-out/last-out (FOLO) structure the borrower never sees.
• It became dominant because it gives private equity sponsors speed, certainty of close and confidentiality, not because it is cheaper or safer. It prices above a senior loan (~450 to 650 bps over the floating benchmark versus ~250 to 350 bps) precisely because it carries junior risk inside a first-lien wrapper. The mechanics are the same whether the deal is priced over SOFR in dollars, SONIA in sterling or EURIBOR in euros.
• The “blended rate” hides a real split: last-out lenders can price at SOFR + 850 bps or more and can recover far less than first-out lenders in a default. In a fund, the question is what share of the book is last-out.
• The Cliffwater Direct Lending Index returned 9.3% in 2025, but that was earned on older, wider-spread loans. Read the yield on any new product as a forward claim, not a backward guarantee.

If you have read anything about private credit in the past two years, you will have met the word “unitranche” sitting next to the word “dominant.” The large-cap unitranche market roughly doubled to $210 billion of activity in 2024, up from $94 billion in 2023, and it is now the default way private credit funds finance a leveraged buyout. This is not a US-only story: Europe is if anything more unitranche-led, with Houlihan Lokey’s MidCapMonitor recording 250 European unitranche transactions in the first half of 2025, up 13% year on year, with debt funds dominating the market. On the structure’s dominance, everyone agrees.

The assumption worth correcting is what people do with “dominant.” Most readers hear it as a signal of safety, as if the market voting for a structure means the structure protects the lender. It does not. Unitranche won because it is fast and certain for the borrower and the private equity sponsor behind them, not because it is the most conservative way to lend. Those are two different claims, and only the first one is true. How a unitranche loan is actually built, what it really costs against the alternatives it replaced, and where the structure quietly lost ground in 2025 are all set out below. If you are weighing private credit as an allocation, the mechanics below are what your yield is being paid for.

What a unitranche loan is

A unitranche loan combines what used to be two separate loans into one. In the old model, a borrower took a senior loan (first claim on the assets, lower rate) from one group of lenders and a subordinated or mezzanine loan (junior claim, higher rate) from another. Two agreements, two lender groups, two negotiations. A unitranche collapses that into a single credit agreement, a single lender or small club, and a single blended interest rate that sits between what the senior and junior pieces would have charged separately.

To the borrower, it looks like one loan. Behind the scenes, the lenders usually split the risk among themselves through a private contract called an Agreement Among Lenders (AAL). The AAL carves the single facility into a “first-out” piece and a “last-out” piece, a structure the market calls first-out/last-out, or FOLO. The first-out lenders get repaid first and take the lower return. The last-out lenders get repaid only after the first-out lenders are made whole, take more risk, and get paid more for it. The borrower never sees the split. They sign one document and deal with one counterparty.

The complexity that used to sit between the borrower and two lender groups now sits between the lenders, invisible to the company being financed. Global Legal Insights calls unitranche “the flagship product of the private credit market,” and distinguishes two common forms: a stretch senior unitranche, which behaves like an ordinary term loan pushed to higher leverage, and the bifurcated first-out/last-out version above, where the AAL governs the payment waterfall, fee and interest allocation, voting, lien priority and enforcement.

Why it became dominant

The reason is not clever financial engineering. It is speed and certainty, sold to the people who actually choose the financing: private equity sponsors buying companies.

When a sponsor is bidding for a target in a competitive auction, the financing has to be locked down fast and it has to close on the terms agreed. A syndicated loan, where a bank arranges the debt and then sells it on to dozens of institutions, carries “flex” risk: the pricing and terms can move against the borrower between signing and funding if the market turns. A unitranche from a single private credit fund removes that. One lender, one term sheet, high certainty of close, and confidentiality because the deal is not shopped around a syndicate. For a sponsor running an M&A process, that certainty is worth paying for.

So unitranche took over because it removes execution risk for the borrower at the exact moment execution risk matters most. Not because it is cheaper, because it is not, as the next section shows. Not because it is safer for the lender either. The market rewarded the structure that served the buyer, and in a private-equity-backed deal the buyer is the sponsor.

What it actually costs: unitranche against the alternatives

This is where a real comparison earns its place, because “blended rate” is doing a lot of hiding. Below is the pricing stack, assembled from 2025 market data, showing where a unitranche sits between the senior and junior debt it replaced. Spreads are quoted over the floating benchmark the loan prices off: SOFR (the Secured Overnight Financing Rate) for dollar deals, SONIA for sterling and EURIBOR for euro deals. The structure and the spread logic are identical across all three; only the base rate changes. All-in cost adds that base rate, and SOFR sat around 4.3% through much of 2025.

Spread ranges compiled from PitchBook leveraged loan data and market reporting; first-lien and unitranche benchmarks per lender disclosures summarised by Chicago Atlantic’s Q3 2025 update, which put lower-middle-market direct lending spreads at SOFR + 450 to 475 bps, a 100 to 150 bps premium over the syndicated market. As at July 2026; spreads move every quarter.

Read the table and the point becomes obvious. A unitranche is not a discount. It prices above a plain senior loan because it is carrying junior risk inside the same wrapper. What the borrower buys is not a lower coupon but a simpler, faster, more certain deal, and they pay a premium in spread for it. The lender, for its part, is being paid a blended rate to hold first-lien-and-junior risk in one line. Whether that blend adequately compensates for the last-out exposure is the whole question, and it is not answered by the word “dominant.”

A worked example: what the blend hides

Take a $200 million unitranche at SOFR + 550 bps, split 70/30 into first-out and last-out through the AAL. Assume SOFR at 4.3%, so the borrower pays roughly 9.8% all-in on the whole facility. Swap the currency and the arithmetic is unchanged: a £200 million facility over SONIA or a €200 million one over EURIBOR splits the same way, because the first-out/last-out mechanics do not care which base rate they sit on.

The lenders do not share that 9.8% evenly. The first-out lenders, holding $140 million with priority, might take something like SOFR + 400 bps. The last-out lenders, holding $60 million and repaid only after the first-out piece is whole, take the residual, which works out materially higher than the headline blend, often SOFR + 850 bps or more once the maths clears. Same loan, same borrower, two very different risk-and-return positions stapled together by a private contract the borrower never reads.

Now stress it. Say the company defaults and the recovery is 70 cents on the dollar, so $140 million comes back on the $200 million. The first-out lenders are made whole. The last-out lenders recover nothing of their $60 million principal from that waterfall until something is left over, and here there is nothing left over. The blended rate told you none of that. This is the reason the structure matters more than the headline yield. In a unitranche you are paid a blend for a position that behaves like senior debt when the borrower performs and like the riskiest slice of the capital structure when it does not, and which one you get depends entirely on which side of the AAL you are on. Most people cannot buy either side directly; they buy a fund holding a mix of these positions. So the question worth asking a fund is plain: how much of the book is last-out.

Where “dominant” started to slip in 2025

Through 2025, unitranche pricing got squeezed, and the squeeze came from the very market unitranche was supposed to have beaten. As the broadly syndicated loan market reopened and competed hard for the same deals, direct lenders had to cut spreads to keep winning them. By the third quarter of 2025, 56% of direct loans tracked by PitchBook LCD were priced below SOFR + 500 bps, up from 37% in the second quarter and just 28% a year earlier. Deals that would have cleared at SOFR + 600 in 2024 were getting done 100 basis points tighter. Volume tells a similar story: Chicago Atlantic reported third-quarter direct lending activity of roughly $60 billion, down from $75 billion a year earlier, as syndicated banks took deals back.

This does not knock unitranche off its perch. It stays the default format. What it changes is what “dominant” is worth. A structure can own the market for how deals get done while the economics of doing those deals get worse for whoever is lending the money. Dominant describes market share, not margin, and in 2025 the margin moved against the lender. If your read on private credit was “dominant structure, therefore durable returns,” the spread compression is the fact that breaks the link between those two ideas.

What this means for the returns you can actually see

Most readers cannot buy a unitranche directly. What you can buy is exposure to a diversified book of them through a fund, a business development company (a listed vehicle that holds direct loans), or an index-tracking product. So the relevant question is what a portfolio of this lending has returned.

The Cliffwater Direct Lending Index, which tracks around 21,000 directly originated US middle-market loans worth roughly $549 billion, returned 9.3% for the 2025 calendar year, with interest income of 10.4% doing the heavy lifting and payment-in-kind income (interest paid in more debt rather than cash) a small 0.7%. Over its 20-year history the index has averaged about 9.5% a year with a single negative year, 2008. That is a genuinely strong record, and it is why capital has flooded in: private credit as an asset class now stands at roughly $1.7 trillion and is forecast to reach $2.64 trillion by 2029, according to Preqin.

Put the two facts next to each other. The returns have been excellent and the pricing is compressing at the same time. A 9.3% index return for 2025 was earned largely on loans written in earlier, wider-spread years. The loans being written into a SOFR + 450 market in 2025 and 2026 lock in thinner economics for the years ahead. Past index performance is describing a market that no longer prices the way it did when those returns were made. None of that is a reason to write off the asset class. It is a reason to read the yield quoted on any new private credit product as a forecast, not a promise backed by history.

This is analysis, not advice, and the difference is the point. Nothing here tells you what belongs in your portfolio. What it should do is let you ask the two questions that separate a real private credit allocation from a marketed one: how much of the underlying book is last-out, and at what spread are new loans being written now. A vehicle that will not answer both is selling you a word, and hoping you never read the AAL underneath it.

FAQs

Is a unitranche loan senior or subordinated debt?

Both, in one facility. From a security standpoint a unitranche is first-lien debt. But inside it, a first-out/last-out split created by the Agreement Among Lenders makes some lenders senior and others subordinated to each other by contract. The borrower deals with a single first-lien loan; the seniority difference lives among the lenders.

Why do borrowers pay more for a unitranche than a senior loan?

Because they are buying speed and certainty, not a discount. A unitranche blends senior and junior debt, so it prices above a standalone senior loan, roughly SOFR + 450 to 650 bps against SOFR + 250 to 350 bps for a plain first-lien term loan in 2025. The premium buys a single lender, a fast close and no syndication flex risk.

Is unitranche still dominant given the spread compression in 2025?

Yes as a structure, but on worse economics for lenders. Unitranche remains the default format for private-credit-backed buyouts, but by the third quarter of 2025, 56% of direct loans priced below SOFR + 500 bps as the syndicated market competed spreads tighter. Dominant describes market share, not margin.

How can an ordinary investor get exposure to unitranche lending?

Rarely directly. Most exposure comes through private credit funds, listed business development companies, or index-tracking products that hold a diversified book of direct loans. The two questions to ask any such vehicle are what share of its loans are last-out, and at what spread it is writing new loans today.

Next read

• The pillar guide: Private Credit explains where direct lending, unitranche and mezzanine sit inside the wider private-debt market.
• For how the largest allocators structure multi-strategy exposure, see Largest Multi-Strategy Hedge Funds: Top Firms Ranked by AUM.