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Changes in the general level of interest rates can affect our net interest income, which is the difference between the
interest income earned on interest-earning assets and the interest expense incurred in connection with our interest-bearing
liabilities, by affecting the spread between our interest-earning assets and interest-bearing liabilities. Changes in the level of
interest rates can also affect the rate of prepayments of our securities and the value of the RMBS that constitute our
investment portfolio, which affects our net income, ability to realize gains from the sale of these assets and ability to borrow,
and the amount that we can borrow against these securities.
We may utilize a variety of financial instruments in order to limit the effects of changes in interest rates on our
operations. The principal instruments that we use are futures contracts, interest rate swaps and swaptions. These
instruments are intended to serve as an economic hedge against future interest rate increases on our repurchase
agreement borrowings.
Hedging techniques are partly based on assumed levels of prepayments of our Agency RMBS.
If
prepayments are slower or faster than assumed, the life of the Agency RMBS will be longer or shorter, which would reduce
the effectiveness of any hedging strategies we may use and may cause losses on such transactions.
Hedging strategies
involving the use of derivative securities are highly complex and may produce volatile returns.
Hedging techniques are also
limited by the rules relating to REIT qualification.
In order to preserve our REIT status, we may be forced to terminate a
hedging transaction at a time when the transaction is most needed.
Our profitability and the value of our investment portfolio (including derivatives used for hedging purposes) may be
adversely affected during any period as a result of changing interest rates, including changes in the forward yield curve.
Our portfolio of PT RMBS is typically comprised of adjustable-rate RMBS (“ARMs”),
fixed-rate RMBS and hybrid
adjustable-rate RMBS. We generally seek to acquire low duration assets that offer high levels of protection from mortgage
prepayments provided that they are reasonably priced by the market.
Although the duration of an individual asset can
change as a result of changes in interest rates, we strive to maintain a hedged PT RMBS portfolio with an effective duration
of less than 2.0. The stated contractual final maturity of the mortgage loans underlying our portfolio of PT RMBS generally
ranges up to 30 years. However, the effect of prepayments of the underlying mortgage loans tends to shorten the resulting
cash flows from our investments substantially. Prepayments occur for various reasons, including refinancing of underlying
mortgages and loan payoffs in connection with home sales, and borrowers paying more than their scheduled loan
payments, which accelerates the amortization of the loans.
The duration of our IO and IIO portfolios will vary greatly depending on the structural features of the securities.
While
prepayment activity will always affect the cash flows associated with the securities, the interest only nature of IOs may
cause their durations to become extremely negative when prepayments are high, and less negative when prepayments are
low.
Prepayments affect the durations of IIOs similarly, but the floating
rate nature of the coupon of IIOs (which is inversely
related to the level of one month LIBOR) causes
their price movements, and model duration, to be affected by changes in
both prepayments and one month LIBOR, both current and anticipated levels.
As a result, the duration of IIO securities will
also vary greatly.
Prepayments on the loans underlying our RMBS can alter the timing of the cash flows from the underlying loans to us.
As a result, we gauge the interest rate sensitivity of our assets by measuring their effective duration. While modified duration
measures the price sensitivity of a bond to movements in interest rates, effective duration captures both the movement in
interest rates and the fact that cash flows to a mortgage related security are altered when interest rates move. Accordingly,
when the contract interest rate on a mortgage loan is substantially above prevailing interest rates in the market, the effective
duration of securities collateralized by such loans can be quite low because of expected prepayments.
We face the risk that the market value of our PT RMBS assets will increase or decrease at different rates than that of
our structured RMBS or liabilities, including our hedging instruments. Accordingly,
we assess our interest rate risk by
estimating the duration of our assets and the duration of our liabilities. We generally calculate duration using various third
party models.
However, empirical results and various third party models may produce different duration numbers for the
same securities.