How Agency CMBS Differs From Private Label CMBS

Agency CMBS are certificates whose payments carry an agency guaranty, so a covered holder looks to the guarantor for timely principal and interest. Private label CMBS have no third-party obligation behind them and depend on protection built into the deal, chiefly the classes that sit below the one being held. The guaranty attaches class by class, because an agency securitization can pair guaranteed senior classes with subordinate classes sold to private capital. Agency paper generally offers greater stability and credit quality, and private label paper typically offers higher yields with greater credit and structural risk.

The guaranty attaches to the class, not the deal label

The first diligence step on any agency CMBS is to identify the exact class. The program name says who sponsored the securitization. The class designation says whether a guarantor stands behind the payments.

In the direct pass-through form, the issuer guarantees timely principal and interest to certificateholders when the securities are issued. In the multi-class form, the pool is split. Senior and interest-only classes may carry a guaranty, and a sequential-pay structure is commonly used for fixed-rate deals.

The same pool of loans also supports classes that carry no guaranty. Mezzanine and subordinate certificates are sold to private capital investors and backed by the same loans.

A private label certificate has no agency obligation anywhere in its structure. Its protection comes from the subordination beneath it and the other terms of the deal documents.

The subordinate slices of an agency deal therefore carry credit exposure much like private label paper, inside an agency transaction.

What a guarantor’s promise covers and what stays with the holder

A guaranty is a promise by a named party to make covered payments on time. Credit work on a covered class becomes work on the guarantor and on the scope of the promise.

The guarantor differs across agency paper. Ginnie Mae certificates carry a direct U.S. government guarantee, while Fannie Mae and Freddie Mac securities are guaranteed by those agencies themselves. All of it is called agency, yet the credit standing behind each promise is not identical.

Agency MBS investors may regard these guarantees as reducing investor credit risk on covered payments. That view concerns credit loss on covered payments.

A bond carries other risks besides credit. The guaranty addresses payment, so the timing of principal still follows the loan terms and the waterfall. Price matters as well. A holder who pays a premium receives the same covered payments, and a faster return of principal shortens the period over which that premium is earned.

Scale of the agency market and who holds the paper

In one measurement taken during a period of market stress, agency CMBS outstanding was around $750 billion, which was 47 percent of $1.6 trillion in total multifamily mortgage debt outstanding. That reading describes the moment it was taken, and balances move with issuance and paydowns.

Flow gives a second scale marker. In one annual total, almost $73 billion of multifamily pass-through securities were issued with the issuer guaranty of timely principal and interest. In the multi-class program, 660 deals carry a total unpaid principal balance of $643.8 billion across deal types.

The holder base has changed. Banks used to be a large part of the agency CMBS market and have mostly vacated it, with some still buying occasionally.

Insurer holdings reflect the split the structure draws: agency paper for stability and credit quality, private label paper for higher yield with greater credit and structural risk.

Sequential pay and lockouts decide when principal arrives

A guaranty protects payment and leaves principal timing to the structure. In a sequential-pay deal, principal collected goes first to the earliest class in the order until its balance reaches zero, then to the next. Two classes backed by one pool can therefore return principal at very different speeds.

The sequential rule has a stated exception. Principal is distributed sequentially unless the outstanding balance of specified subordinate certificates has been reduced to zero. A cash flow model that applies only the ordinary sequence leaves that second state unmodeled.

Loan terms add a separate layer. In the multi-class program, 10-year loans typically carry a 9.5-year lockout or defeasance period, which leaves only about the final half year of the term open to voluntary prepayment.

The loan terms limit what borrowers can prepay. The waterfall decides which class receives the cash that does arrive. A model needs both layers before it can project the life of a class.

“Typically, you have 10-year loans and then they have a 9.5 year lockout or a nine and a half year defeasance period, meaning that loan is strict.”

What the extra yield on private label paper pays for

Private label CMBS typically offer higher yields with greater credit and structural risks, so the spread compensates for exposures that can be named and sized. A covered agency holder has protection against those exposures to the extent provided by the guaranty.

A yield is a function of price and assumed cash flows. For a class that can lose principal, the assumed loss amount and its timing move the yield directly. Two yields compare cleanly only when both belong to the same position in the payment order.

A subordinate class inside an agency deal and a senior class inside a private label deal show the problem. The first carries no guaranty. The second is protected by the classes beneath it. Position in the waterfall and the presence of a guaranty set their risk, and the agency or private label wrapper does not.

Worked example: the same senior class with and without an agency guaranty

The figures are hypothetical and illustrative. A pool of $120,000,000 supports a senior class of $100,000,000, which leaves a subordinate class of $20,000,000 (120,000,000 minus 100,000,000). An investor buys $10,000,000 of the senior class at par. That is 10 percent of the class (10,000,000 divided by 100,000,000, multiplied by 100). In the agency version the senior class carries a guaranty and the guarantor performs. In the private label version the classes are identical and no guaranty exists. Both cases use the same capital and one period, and look at principal only.

Base case. The pool takes a $12,000,000 principal loss, which is 10 percent of the pool (12,000,000 divided by 120,000,000, multiplied by 100). The subordinate class absorbs all of it and is left with $8,000,000 (20,000,000 minus 12,000,000). The senior class takes no loss, so the investor receives $10,000,000 in both versions and the guaranty pays $0.

Stressed case. The pool takes a $30,000,000 principal loss, which is 25 percent of the pool (30,000,000 divided by 120,000,000, multiplied by 100). The subordinate class absorbs $20,000,000 and is left at $0 (20,000,000 minus 20,000,000). The shortfall reaching the senior class is $10,000,000 (30,000,000 minus 20,000,000), which is 10 percent of the senior class (10,000,000 divided by 100,000,000, multiplied by 100).

The investor holds 10 percent of the senior class, so the investor’s share of the shortfall is $1,000,000 (10,000,000 multiplied by 10,000,000, divided by 100,000,000). In the private label version the investor receives $9,000,000 (10,000,000 minus 1,000,000), a principal loss of 10 percent (1,000,000 divided by 10,000,000, multiplied by 100). In the agency version the pool pays $9,000,000 and the guarantor pays the $1,000,000 gap, so the investor receives $10,000,000 (9,000,000 plus 1,000,000) and the principal loss is 0 percent (0 divided by 10,000,000, multiplied by 100).

The two versions differ by $1,000,000 in the stressed case (10,000,000 minus 9,000,000) and by nothing in the base case. Subordination decides when the senior class first takes a loss, and the guaranty decides who bears it afterward. Interest, price changes and the timing of principal are excluded, so none of these figures is a total return.

Mistakes that distort agency versus private label comparisons

Assigning the guaranty to every class in an agency deal confuses the transaction category with the certificate obligation. Mezzanine and subordinate certificates in an agency securitization are sold to private capital and are backed by the same loans as the senior classes. The guaranty covers only the classes it is written for.

Treating subordination and a guaranty as one credit enhancement hides who pays. Subordination is a finite balance that absorbs losses until it reaches zero, as the stressed case shows when $20,000,000 of subordinate principal is exhausted. A guaranty is an obligation of the guarantor for covered payments. A senior class can have both, and each answers a different part of the loss question.

Reading a loan lockout as the certificate’s principal schedule mixes two contracts. A 9.5-year lockout on a 10-year loan limits the borrower’s prepayment choices. Which class receives the cash that does arrive is a waterfall question, and the sequential rule changes once the specified subordinate balance reaches zero.

Quoting one market-size snapshot as the present market overstates what the data says. Agency CMBS of around $750 billion, or 47 percent of $1.6 trillion in multifamily mortgage debt, describes the moment the figure was taken.

Comparing yields without matching the position in the payment order produces a spread that proves little. Private label yields are higher because they carry greater credit and structural risks, and a yield set against a covered class does not isolate how much of the spread pays for credit exposure.

Paying a premium for a covered class and ignoring principal timing misprices the paper. The guaranty covers payments, and a faster return of principal shortens the period over which the premium is earned.

Checklist questions for an agency versus private label review

Which class is being purchased, and does it carry the guaranty? The obligation attaches to the certificate, so the class designation settles the first question.

Who is the guarantor, and what does the guaranty cover? A direct government guarantee and an agency guaranty rest on different credits, and the scope defines which shortfalls are covered.

Which classes absorb loss before the purchased class? Their balances measure the subordination cushion available in a stressed case.

What principal sequence applies while the specified subordinate balances remain outstanding? The order sets which class receives collected principal first.

What changes once those subordinate balances reach zero? The sequential rule stops governing at that point, so a model needs a second branch.

What lockout or defeasance terms sit on the underlying loans? Those terms shape how much prepayment can reach the waterfall.

Does the yield comparison use the same position in the payment order on both sides? A spread between unlike positions mixes credit compensation with structural differences.

Does the analysis keep principal recovery separate from total return? Principal loss arithmetic leaves out interest and any change in the price of the certificate.