Title: Mortgage Markets and Mortgage Backed Securities
1Mortgage Markets and Mortgage Backed Securities
2Brief History of Mortgages
- 5,000 years ago Babylonians used land as security
to encourage the building of dikes and dams - Egyptians used surveys to describe land plots
ranked by fertility from flooding of the Nile - Romans introduced the fiducia a document that was
a title to land. Roman Law defined a hypotheca
or pledge that resembled lien theory today
3Brief History of Mortgages
- Following the decline of Roman empire, Germanic
law developed the idea to use land as security in
borrowers agreements, this practice was referred
to as a gage - William of Normandy introduced the Germanic gage
system into early English law. The French word
mort (dead or frozen) was combined with gage to
produce a locked pledge or mort-gage on property.
4The US mortgage market
- Establishment of mortgage companies in the the
1800s to finance land purchases by farmers in
the Midwest. - By 1900 there were approximately 200 mortgage
companies with outstanding loan values totaling
4 billion - Early mortgages paid interest semiannually,
nonamortizing with a balloon payment at the end
(as short as 3 to 5 years)
5History of Mortgage Market 1910-1925
- Farm Mortgage Bankers Association formed in 1914.
Became Mortgage Bankers Association in 1923 as
markets expanded into more urban settings. - During 1920s a secondary mortgage market
started to form. - Mortgage companies issued mortgage participation
bonds that guaranteed payment of principal and
interest to the owners (backed by the mortgages)
6History of Mortgage Market1925-1930
- Early 1920s fast appreciation of land value (50
to 75 annually). Assumption was that inflation
would help bail out poor loans and that boom in
prices assured payments. - 1929 stock market crash spilled over to mortgage
market. A majority of the mortgage companies
went out of business. - Foreclosures brought about a surplus of real
estate and values decreased to half of their high
during 1927 and 28.
7History of Mortgage Market1930-1935
- Majority of foreclosures were on second and third
mortgages. From 1931 to 1935 foreclosures
averaged 250,000 annually. - Moratoriums on foreclosures provided some relief
in the Midwest states where farms were also
experiencing the dust bowl. - Feb 8, 1933 Iowa issued first law suspending
foreclosures (for 2 years), within 18 month 27
other states had enacted similar laws.
8History of Mortgage Market1930-1935
- 1933 Home Owners Loan Corporation was formed by
the federal government. - Used proceeds of government bond sales to
refinance homeowners mortgages. - The HOLC acquired defaulted mortgages, refinanced
them and put the loans on a monthly payment
schedule - Refinanced over 1 million homes in first three
years.
9History of Mortgage Market1930-1935
- 1934 Federal Housing Administration was formed
- Primary objectives
- The improvement of the nations housing standards
- To provide an adequate home financing system
- To be a stabilizing influence on residential
mortgage markets. - Furthered the concept of amortizing loans and
provided intermediary to channel funds to needed
areas
10History of Mortgage Market 1930-1940
- FHA insured mortgages provided dependability
and transferability to the market and reduced
risk. - 1938 Federal National Mortgage Association
(Fannie Mae) was formed to provide a secondary
market for FHA insured loans.
11History of Mortgage MarketPost WWII
- After WWII The government established the
Veterans Administration which helped fuel a
housing boom. - The VA offered veterans financing for homes with
little or no down payment. - Private sector was very liquid and wanted to
increase return form bond holdings that had been
purchased to fund the war. Mortgages were a
perfect vehicle to do this.
12History of Mortgage Market
- 1948 Fannie Mae completes first secondary market
transaction with the purchase of VA loans. - 1949 Prudential Federal, Salt Lake City sells
1.5 million in FHA/VA loans to First Federal in
NY First private secondary market transaction - 1954 Fannie Mae was reorganized. New charter
made it part private part federal owned
13History of Mortgage Market
- 1963 FHLB and FSLIC issue nationwide regulations
permitting SLs to purchase conventional
residential loans (Up to 3 of Assets) - SLs allowed to make loans to non association
members
14History of Mortgage Market 1968
- Fannie Mae becomes entirely privately held
- Ginnie Mae is established to oversee special
assistance (FHA and VA) programs - Ginnie Mae has authority to guarantee timely
payments of PI on securities issued by lenders
of FHA and VA loans. Guarantees backed by full
faith and credit of US Treasury.
15History of Mortgage Market 1970
- Ginnie Mae guarantees first issuance of mortgage
pass throughs backed by FHA and VA mortgages
State of New Jersey pension fund was the buyer. - Federal Home Loan Mortgage Corporation (Freddie
Mac) chartered as secondary marketing arm of
FHLB, issues first participation certificate in
1971 - Fannie Mae granted authority to purchase
conventional mortgages
16History of Mortgage Market 1970s
- 1971 Fannie Mae and Freddie Mac issue uniform
loan documents. - 1972 Fannie Mae and Freddie Mac start purchasing
conventional single family mortgages - 1975 CBOT offers futures trading on Ginnie Mae
MBSs - 1976 total secondary market exceed 43 Million
- 1977 First Private pass-throughs issued by Bank
of America San Francisco and First Federal Chicago
17History of Mortgage Market 1980s
- 1981 Freddie Mac and Fannie Mae institute loan
swap programs allowing SLs to exchange loans
held in portfolio for MBS - A large quantity of adjustable rate mortgage
products enter the market - 1983 Freddie Mac issues first CMO
- Ginnie Mae introduces GNMA-II program to attract
pension fund money - Freddie Mac and Fannie maw attempt to
standardize ARMs that they will use.
18History of Mortgage Market 1980s
- 1984 ARM half of all residential loans closed.
- CBOT initiates GNMA-II futures contracts
- Ginnie Mae MBS issuance hits 200 Billion
- Ginnie Mae issues first ARM MBS backed by FHA
insured ARM loans - Congress passes legislation to tax Freddie Mac
- 1986 Fannie Mae issues its first stripped
securities - A record 48 billion CMOs are offered
- First CMO by Freddie Mac based on 15 year
mortgages
19The Mortgage Market
- The Primary Market
- Mortgage Originators
- Thrifts, Commercial banks and mortgage brokers
20Origination income
- Origination Fee - expressed in terms of points --
each point represents 1 of the borrowed funds --
Origination fee of 3 points on 100,000 mortgage
is 3,000 - Secondary market profit -- selling the mortgage
obligation at a price higher than it originally
cost. - Servicing Fee - Collecting monthly payments,
forwarding proceeds to owners of the loan,
sending payment notices, maintaining records,
furnishing tax info etc
21Servicing Fees
- Servicing fees are generally a portion of the
mortgage rate and is often referred to as
servicing spread.
22The mortgage origination process
- Applicant submits info relating to the property
and income. Originator performs credit report
and looks at the probability of repayment. - PTI -- payment to income ratio (monthly payment
/ monthly income) - LTV -- loan to value ratio (Loan amount /
Valuation ) - Commitment letter-- outlines the terms available
for the next 30 to 60 days. The borrower pays a
commitment fee which will be lost if no loan is
taken out.
23Post Loan Options
- After making the loan the originator has one of
three options - Hold the mortgage in their portfolio.
- Sell the mortgage to an investor (who will either
hold the mortgage or use it as collateral),
possibly continuing to service the mortgage. - Use the mortgage as collateral to issue a
security (securitizing the mortgage)
24Origination Risks
- Price Risk If rates increase the originator has
already committed to charging lower rates -- - Can protect against price risk with a second
commitment from a secondary market participant
that agrees to buy the given loan at a futures
point in time for a given price. - However this brings a second risk -- if rates
decline the borrower may not close and the
originator is locked into providing the above
market return. - Fall out Risk. Risk that some individuals issued
commitment letters will not close
25Mortgage Construction
- Traditional Fixed Rate Mortgage (fixed-rate
level-payment, fully amortized mortgage) - Principal and interest are amortized over the
life of the mortgage. - The payment is determined with the basic PV of an
annuity formula
26Amortization of a Loan
- You want to borrow 1,000 and pay it off over
three years. Assume that you are charged 6 each
year. How much will your payment be? - 1,000 PV PMT ????
- 1,000 PMT (PVIFA6,3)
- 1,000 PMT(2.67)
- PMT 374.11
27Amortization
- You pay a total of 374.11(3) 1,122.33
- A portion of each payment represents interest
charges. - You can find the amount of interest by
multiplying the beginning balance each payment
period by the interest rate. - At the beginning the balance is 1,000 so there
is 1,000(.06) 60 in interest.
28Amortization
- Beginning
Ending - Year Balance Payment Interest Principal
Balance
1
1,000
374.11
60.00
314.11
685.89
2
685.89
374.11
41.15
332.96
352.93
3
352.93
374.11
21.18
352.93
0.00
29Amortization 30 yr Mortgage150,000 5.85
- Beginning
Ending - Year Balance Payment Interest Principal
Balance
1
150,000
884.91
731.25
153.6614
149,846.34
154.41
2
149,846
884.91
730.50
149691.93
1756.97
359
884.91
8.57
876.35
880.62
0
880.62
880.62
360
884.91
4.29
30Servicing Fee Revisited
- Since the servicing fee is generally a portion of
the interest payment the actual fee income will
decline throughout the life of the mortgage as
interest decline.
31Prepayments and CF Uncertainty
- Generally there is not a penalty for prepaying
the principle early. When a prepayment is made
for less the entire balance it is referred to as
a curtailment. - Some mortgages however do have a lock out period
or penalty period which can limit or prohibit
prepayment.
32Origination Problems
- Mismatch
- Institutions are borrowing short and lending
long) - Tilt
- The real burden of the loan to the borrower is
in the early years of the loan. Since inflation
decreases the real burden of their payments over
time.
33Adjustable Rate Mortgages
- The loan rate is reset periodically using a base
or reference rate. - The rate might reset every month, year, 2 years 5
years etc.. - Reference Rate
- Market determined
- Cost of Funds
34ARM Features
- Usually offer an initial rate less than
prevailing fixed rate (teaser rate). - At reset date reference rate plus a spread
determines the rate. - There may be caps and floors on the rates, both
periodic and lifetime.
35Balloon Two Step Mortgages
- Allows for rollover and renegotiation of the loan
at periodic intervals. - Different from ARM the future rate is not set
from base rate. - Loan is extended if certain requirements are met.
- 30 due in 5 is a thirty year mortgage where the
remaining principal is due (or refinanced) after
five years. - Two step rates once based upon a specified rate
36Solutions to the tilt problem
- ARMs address the mismatch problem by allowing for
longer term lending at a short term rate. - The tilt problem has creates the market for other
types of products - Graduated Payment Mortgages
- Price -level Adjusted Mortgage.
- Dual Rate Mortgage
37Graduated Payment Mortgages
- The mortgage payment increases each year at the
beginning of the loan then hits a level amount
for the remainder of the loan. - This actually produces negative amortization
since in the beginning the total amount does not
cover the interest on the loan. - Specified in the loan are The fixed rate, the
rate of growth for the first few years, the
number of years over which the payment will
increase
38Graduated Payment Mortgages
- Example 30 year, 10 mortgage on 100,000 with
the payment growing at 7.5 each year for the
first 5 years. - Fixed rate payment would be 877.5715
- GPM Payments
- Year Payment Year Payment
- 1 667.04 2 717.06
- 3 770.84 4 828.66
- 5 890.80 6-30 957.62
39Price Level Adjusted Mortgages
- Monthly payment is designed to be level in
purchasing power. The fixed rate of interest is
a real rate of interest. - The monthly payment is then calculated using the
real rate just as a regular mortgage would be. - The actual payment is then adjusted based upon
the rate of inflation.
40Dual Rate Mortgages
- Similar to the PLAM except the amount owed is
based on a floating short term rate. - To establish the mortgage you need
- the payment rte (the real rate of interest that
is fixed for the life of the loan), - the effective or debiting rate that changes
periodically and - the maturity of the mortgage.
41Other plans
- Growing Equity Mortgage Similar to the GPM
except there is no negative amortization. The
increase in payment will serve to pay off the
principal quicker than a traditional mortgage. - Lenders will be willing to lend a t a lower rate
(if the yield curve slopes up) and borrowers
increase payment solving tilt problem - High LTV loans eliminates high down payments by
financing up to 100 of the value of the home
plus closing costs.
42Other Plans
- Alt-A loans Requires alternate documentation of
income for special cases such as self employed
individuals. Rtes are generally 75 basis points
to 125 basis points above other rates - Sub Prime Loans Borrowers who have had credit
problems. Rates based upon different risk grades
43Risks Faced by Mortgage Investors
- Credit Risk
- Risk of default by the borrower
- Liquidity risk
- Even with the secondary markets, individual
loans are relatively illiquid - Price Risk
- Value moves opposite changes in interest rates
- Prepayment Risk
- The borrower may prepay early
44Mortgage Pass Through Securities
- Interest and Principle are collected by the
issuer of the pass through on a pool of mortgages
who then transfers (passes through) the payments
to the owners of new securities backed by the
mortgages. - Neither the amount or timing of the cash flows
actually matches the cash flows on the pool of
mortgages. - When a mortgage is included in a pool it is said
to be securitized.
45Cash Flows
- Neither the amount or timing of the cash flows
actually matches the cash flows on the pool of
mortgages. - Servicing and other fees are removed from the
cash flows received from the mortgage prior to
being passed through to the holder of the pass
through security. There is also a delay in the
pass through process.
46Terminology
- The pool of mortgages will have a variety of
different rtes and maturities. Therefore, the
description of the pass through is based upon
weighted averages of the coupon and maturity.
47WAC, WAM and WARM
- WAC weighted average coupon rate
- Weighting the mortgage rate of each mortgage in
the pool by the outstanding principal balance - WAM weighted average maturity
- Weighting the number of months to maturity of
each mortgage in the pool by the outstanding
principal balance - WARM weighted average remaining maturity
- After prepayments have started the maturity
changes.
48Guarantee Types
- Fully Modified Pass Throughs Guarantees that
the principal and interest will be paid
regardless of whether the borrower is late. - Modified Pass Through Guarantees the timely
payment of interest, the principal is passed
through when it is received.
49Ginnie Mae
- Ginnie Mae pass throughs are guaranteed by the US
treasury. - Issues Mortgage backed securities which are fully
modified pass throughs - All mortgages are FHA, VA or Farmers Home
Administration loans
50Fannie Mae
- Sells mortgage backed securities and channels the
funds to lenders by buying mortgages. The
institution may continue to service the original
mortgage. - All are fully modified pass throughs, but there
is no government guarantee of payment - Both Ginnie Mae and Fannie Mae securities are
commonly referred to as Mortgage Backed
Securities
51Freddie Mac (FHLMC)
- Participation Certificates sold by the agency are
used to finance the origination of conventional
mortgages. Usually PC only guarantee that the
interest payment will be made. The principle
payment is passed through as it is received. The
guarantee is not backed by the federal government
as is the case in Ginnie Mae. - Most are fully modified (new issues are)
52 Participation Certificates
- Two main programs
- Cash program FHLMC buys mortgages from the issuer
and issues PC's based on the mortgages. - Guarantor / Swap program -- Allows thrifts to
swap mortgages for PC's based on the mortgages.
The institution can swap mortgages selling below
par for without recognizing an accounting loss!
- The PC is then
- Held as an investment
- used as collateral for borrowing
- sold
53Comparison of rates
- The pass through rate is less than that of the
mortgage pool. The difference accounts for
service and guaranteeing fees. - The timing is also different to allow for the
payment of the mortgages (on the first of the
month) prior to the pass through occurring.
54Creation of a GNMA pass through
- The loan pool must have standard features in
terms of single family or mutli family, maturity
etc. - The originators forward the pool to GNMA with
supporting documentation requesting GNMA to
guarantee the securities to be backed by the pool - After review a pool number is assigned if the
pool is accepted
55Creation of a GNMA pass through
- The originators transfer the mortgage documents
to custodial agents and send pool documents to
GNMA - Originators look for investors (dealers,
investment banks etc) willing to buy a given
amount at a specified price
56Creation continued
- GNMA issues the guarantee following review of the
documentation. - Originators continue to service the loans.
- The GNMA MBS is not a debt of the issuer, it is a
representation of the loan pool with payments
guaranteed by Ginnie Mae
57Fees for a typical GNMA pool
- 44 basis points are retained by the servicer for
servicing fees - Ginnie Mae receives 6 basis points for the
guarantee. The issuer is guaranteeing Ginnie Mae
against defaults by the homeowner and Ginnie Mae
guarantees against defaults by the issuer. - The investor then receives approximately 50 basis
points less than the coupon of the loan
portfolio.
58Price Quotes
- GNMAs are quoted in 1/32 of a point
- Quotes depend upon a pool factor pf(t)
representing the of the initial mortgage pool
balance outstanding
59Market Value
- Consider an investor with 20 million of a 100
million issue with a pool factor of .9 and a
price of 9316/32 - Par value remaining 20 (.9) 18 million
- The value is then price x par value x pool factor
- Market Value (.9350) (20)(.9) 16.38 Million
- You would need to also account for accrued
interest to find the actual cash price.
60Accrued interest
- Assume a coupon rate of 9 and 20 days into the
month
61Trading and Settlement Procedures
- Agency pass throughs are identified by a pool
prefix number. - TBA trade a trade based on an agency pass
through prior to the pool of mortgages being
established. Generally, there will prior
agreement on agency type, program, coupon rates,
and settlement date
62Market references
- At a given point in time there may be many
seasoned issues of an agency security with the
same coupon rate. - For example in early 2000 there were more than
30,000 pools of 30 year Ginnie Mae MBSs with a
coupon rate of 9. - Each pool may be from a different area of the
country or from several regions. - Dealers will refer to all of these as Ginnie Mae
9s even though they have different prepayment
characteristics. If the investor does not specify
a pool number, the dealer has the option to
deliver any of the pools.
63Non Agency Pass Through Securities
- Often non agency mortgage pass throughs will
attempt to increase their rating - External Credit Enhancement
- third party guarantees of losses up to a
predetermined amount. Often these are in the
form of a corporate guarantee , a letter of
credit, pool insurance or bond insurance - Internal Credit Enhancement
- Reserve funds
- Over collateralization
- Senior/subordinated structure
64Prepayment conventions
- In order to value a MBS the pattern of
prepayments needs to be forecasted. - To do this the pool needs to be looked at and
some assumptions need to be made concerning the
payment of the pool.
65Measuring prepayment
- Constant Monthly Mortality
- Assume that there is a 0.5 chance that the
mortgage will be prepaid after the first year.
The 0.5 is the single month mortality rate (or
SMM) - Given the SMM it is easy to compute the
probability that the mortgage will be retired in
the next month. - The probability that the mortgage survived the
first month is 1-0.005 .995 or 99.5
66Measuring Prepayment
- Given a 99.5 chance that the mortgage survived
the first month, and a 0.5 SMM for the second
month the probability that the mortgage will be
retired in the second month is 0.50(.995)
0.4975 - Continuing in the same manner the yearly
prepayment rate could be found.
67Conditional Prepayment Rate
- Let CPR be the conditional prepayment rate. The
probability that the mortgage survives one year
is (1-SMM)12 which should equal (1-CPR) - or
- (1-SMM)12(1-CPR) CPR 1-(1-SMM)12
- this assumes that prepayments will be the same
through time which is not consistent with the
empirical evidence
68Conditional Prepayment Rate (CPR)
- The industry convention is to use an annual
prepayment rate based upon the historical
prepayment observed by the FHA. The CPR can then
be easily transferred back to a monthly rate (the
single month mortality rate (SMM)) - SMM 1 - (1-CPR)1/12
-
- If the CPR is 6 the SMM is equal to
- 1 - (1-.06)1/12 .005143
69 Calculations
- Prepayment based upon the SMM
- Estimated Prepayment for month t
- Using the SMM above assume we own a pass through
with a beginning balance of 290 million and
principal repayment of 3 million scheduled - Estimated Prepayment would be
- .005143(290,000,000-3,000,000)1,476,041
70The PSA benchmark
- The Public Securities Association prepayment
benchmark is expressed as a monthly series of
conditional prepayment rates. - The PSA benchmark assumes that prepayments start
slow then increase -
71Market Convention
- The CPR has been shown to level off after thirty
months. The standard CPR used is .2 for the
first month then increasing at .2 each month
until 6 is reached for the thirtieth month and
every month thereafter.
72100 PSA
- 100 PSA assumes market convention speed of
prepayment - Using the convention of a CPR of 0.2 for the
first month increased by 0.2 each month for the
next 30 months - After 30 periods a CPR of 6 for the remaining
years of the mortgage - PSA is then expressed as a percentage of 100 PSA
benchmark.
73PSA benchmark
- For Example a PSA of 150 means that the pool
prepays at an expected rate 1.5 times as fast as
the PSA benchmark - Notice the CPR is a multiple of the PSA not the
SMM
74Monthly cash flow construction(exhibit 3 in book)
- Assume that you have a 400 Million 7.5 pass
through with a WAC of 8.125 and a WAM of 357
months assuming 100PSA - Note the pass through has been seasoned three
months this makes the CPR 0.8
75Exhibit 3
- The SMM for the first month is then
- SMM1-(1-CPR)1/121-(1-0.008)1/120.000669124
- The scheduled mortgage payment would be
- 400,000,000PMT(PVIFA357,8.125/12)2,975,868.24
- (this changes with each payment due to prepayment)
76Monthly cash flow construction
- Interest is found from the pass through rate of
7.5 400,000,000(.075)/12 2,500,000 - The scheduled principal is found using the WAC
and the payment calculated earlier. - Total interest scheduled from the pool is
400,000,000(.08125)/12 2,708,333.333 - Given a payment of 2,975,868.24 the scheduled
principal is 2,975,868.24 - 2,708,333.333 - 267,534.91
77Monthly Cash Flow Construction
- The expected prepayment for the month is then
found using - For the first month this is equal to
- .000669124(400,000,000-267,534.91)
- 267,470.58
- total principal is then equal to
- 267,534.91267,470.58535,005.49
78Monthly Cash Flow Construction
- Total Cash Flow is then the sum of the interest
paid to the pass through investor and the total
principal - 2,500,000 535,005.493,035,005.49
- the next months outstanding balance is then
reduced by the amount of principal - 4,000,000-535,005.49 399,464,994.51
- the next month would proceed the same way with
the exception of the scheduled mortgage payment.
79Note
- The PSA convention is the result of past
experience on FHA prepayments. The empirical
evidence suggests a level CPR after 30 months of
6. The first 29 months are just a linear
approximation starting at zero months and ending
at 29. - The same method is used regardless of the
maturity of the pass through, and the rate (ARM
or fixed.) It is at best an quick and easy
estimate.
80Non Agency CPR convention
- Defaults and other problems characterize the
nonagency pass throughs, therefore there is a PSA
standard default assumption (SDA) - 0.02 fro the first month increasing by 0.02
each month up to .6 at 30 months - .6 form 30 to 60 months
- 61 months to 120 months default rates decline to
0.03 - 120 to maturity default rates remain at 0.03
81Factors Affecting Prepayment
- Prevailing Mortgage Rates
- Characteristics of the Mortgage Pool
- Seasonal Factors
- General Economic Activity
82Factors Influencing Prepayment
- Prevailing Mortgage Rates
- Spread between Original Rate and Prevailing rate
- If the original rate is greater than the
prevailing rate there is a higher probability of
prepayment. These mortgages are often referred
to a premium mortgages. (the opposite case would
produce discount mortgages) - Path of Rates
- If rates went up then down prepayments will be
higher. If rates decreased then increased and
decreased again, prepayments will not be as high
since many took advantage the first time.
83Factors Influencing Prepayment
- Prevailing Mortgage Rates
- Level of rates
- As the level of rates declines turnover
increases as more homes become affordable.
84Factors Influencing Prepayment
- Characteristics of Underlying Mortgage Loans
- Seasonality (more in the Spring and summer less
in the winter) - Age of Mortgage Prepayments are higher during the
early stages of the mortgage and the final
periods prior to maturity - Type of Loan (ARM, balloon etc)
85Factors Influencing Prepayment
- Seasonality (more in the Spring and summer less
in the winter) - This mirrors the amount of home buying activity.
- This results in a slight lag of the impact of
prepayments on the MBS market since there is a
lag in passing through the prepayments.
86Factors Influencing Prepayment
- General Economic Factors
- Housing Costs
- Geographic Location
- Family Circumstances
- Economic Activity
87Extension and Contraction Risk
- The investor is not sure of the timing of the
cash flows since it depends upon the timing of
the prepayments. Therefore they face other risks - Extension Risk there is a change in the market
that causes fewer prepayments and the length of
time prior to the repayment increases due to
fewer prepayments - Contraction risk - Prepayments increase as rtes
decline causing shortening of the length of the
MBS and reinvestment risk.
88Collateralized Mortgage Obligations.
- Provide semiannual payments
- The payment of principle is allocated among
different tranches that represent the repayment
of principle. - Allows investors to attempt to match their
willingness to accept prepayment risk to a
security -
89Average Life
- This measure represents the average time to
receipt of principal repayments.
90Sequential pay CMO
- The first Tranche receives principle until the
total principle in the tranche is paid off. The
CMO will be explained by a Weighted average
maturity and a weighted average coupon that
represents the mortgages in the CMO. - The actual timing of the payoff will depend upon
the prepayment rate. The speed of prepayment can
be estimated, but it will not be know in advance.
91Example Same starting point as before
- Assume that you have a 400 Million 7.5 pass
through with a WAC of 8.125 and a WAM of 357
months assuming 100PSA - Four payment tranches
- Tranche Par Amount Coupon
- A 194,500,000 7.5
- B 36,000,000 7.5
- C 96,500,000 7.5
- D 73,000,000 7.5
92Example continued
- Each tranche received interest upon the
outstanding principal in the tranche. Tranche B
receives no principal until Tranche A has
received all of its principal likewise tranche C
follows B and D follows C. - Therefore after the fist period, tranche B
receives 36,000,000(.075)/12 225,000 - Tranche B continues to receive 225,000 each
period until the principal has been paid off to
tranche A. The pay down of principal is
calculated as before
93CMO
- The CMO has allowed investors to choose a tranche
that best matches their desire to accept
prepayment risk (match the timing of cash flows
to their needs). - However, there is still variability in the actual
timing of the tranches since prepayments may not
occur at the estimated speed.
94Accrual Tranches
- In the example all the tranches receive interest
payments. Often this is not the case. It is
possible for one or more tranches to be an
accrual bond. - The interest that would have been paid on the
tranche now goes to paying down the debt on the
earlier tranche. This shortens the maturity of
the other tranches.
95Floating Rate Tranches
- Any fixed rate tranche can be converted to a
floating rte and inverse floating rate tranche
(adding a tranche to the total structure of the
CMO) - Whatever portion of the balance is not the
floater will be the balance of the inverse
floater. - You can also use only a portion of the tranche to
create the floaters.
96Interest Only and Principal Only
- Another structure is to allocate only interest or
only principal to a given tranche. - The IO investor will want the prepayments to be
slow since it extends the life of the CMO. The
PO investor will prefer that the prepayments
arrive quickly
97Structured IO
- IO tranches are often referred to as structured
IOs to distinguish them from a stripped IO. - In this case the coupon rate for one tranche is
different from the coupon rate on the collateral.
For example the rate may be less than the
interest rate on the collateral. The excess
interest is then allocated to a separate tranche.
98Notional IO classes
- This is a class that receives the excess coupon
interest. It has no par value, only a notional
value upon which the payments are based.
99Planned Amortization classes
- Includes a set principal payment schedule which
must be followed (if the actual prepayments fall
within a given window then a schedule of
principal payments is followed). - PAC bondholders have priority over the other
classes within a CMO. Therefore PAC bonds come
at the expense of support or companion bonds
which absorb the prepayment risk (they forego
principal)
100Planned Amortization Class Tranche (PAC) CMOs
- If prepayments are within a specified range, the
cash flow pattern is known. - PAC bondholders have priority over the other
tranches in the issue. - The non PAC bonds are termed support or companion
bonds. - The minimum is based off of a range of PSA
assumes an upper and lower collar.
101PAC Bonds
- The guaranteed principal payment is the minimum
of the principal repayments of the two possible
PSAs. - The prepayment can occur even if prepayment
occurs at a rate different than the original
collars
102PAC bonds
- The support bonds provide protection against both
extension and contraction risk. Therefore the
PAC will not shorten even outside of the initial
PAC bands. - The wider band of guaranteed prepayments creates
an effective collar in which the prepayments stay
constant.
103PAC Bonds
- The support bond will not receive any principal
until the PAC has received all of the scheduled
prepayment. - If the prepayment is slower than scheduled any
principal that might have gone to the support
bond (if the schedule was met) will now go tot
the PAC.
104PAC Bonds
- If the prepayment is faster than originally
planned the support bond will receive faster
prepayments, eliminating the PAC paying off
quicker. - If the principal of the support bond is paid off
early then the PAC will decrease in maturity.
105Quick Question
- Will the schedule of principal repayments be
satisfied if prepayments are faster than the
initial upper collar? - It depends upon when the prepayments occur. The
initial assumption was that the support would be
eliminated at the upper collar. It repayments
were initially slow, there is extra support
available.
106Quick Question 2
- Will the schedule of principal repayment be
satisfied as long as prepayments stay within the
initial collar? - Not always the initial structure only guarantees
that the schedule will be met if it is at either
of the extremes. If prepayment varies there is a
possibility that the PAC is busted.
107Answer continued
- IF the PAC has been prepaying at the faster PSA
the amount of support decreases and the lower
collar of the effective collar increases above
the initial collar.
108Final Question
- Given the first two questions does a wider
initial collar imply that there is less risk that
the repayment will not fit the schedule? - No the actual prepayment experience once the PAC
is seasoned is what is important. - Given prepayment experience, the effective collar
is what should be investigated.
109Increasing Prepayment Protection
- Lockout Structure Eliminating the earlier or
shorter PAC from the package creating more
support bonds - Changing the prepayment rules in the event that
all support bonds are paid off. One possible
structure reverse PAC -- requires any extra
principal to go to the longer maturity PACs
110Targeted Amortization Class
- Instead of guaranteeing a range of rates
initially a TAC bond guarantees a specific
targeted rate. The bond is therefore only
protected against contraction risk, not extension
risk.
111Stripped Mortgage Backs
- 1) Synthetic coupon pass throughs
- results in a cash flow different than the
underlying coupon - 2) IO and PO strips
- Principal is at a discount from par. IO has a
notional value. - 3) CMO strips
112Principal Only Strips
- The principal only strip is purchased at a
substantial discount to par value. - The faster the prepayments, the higher the return
to the investor since the return is determined
only by the speed with which the investor will
receive the principal
113Interest Only Strips
- The Interest is based upon the amount of
prepayments outstanding therefore the investor
will hope that the prepayments will be slow. - It is possible for the IO investor to not recover
the amount originally paid if prepayments are too
fast.