Mortgage-backed security hedging systems and methods

1. A computer assisted method of computing hedge ratios for one or more hedge instruments to hedge a portfolio of mortgage-backed securities belonging to a mortgage sector, the sector having multiple different coupons in a coupon stack, the method comprising:

calculating, by a computer system, a vector of relative coupon durations for the coupons in the coupon stack based on a linear system [Δ{circumflex over (p)}] k =[{tilde over (W)}] k {circumflex over (d)}, where Δ{circumflex over (p)} is a vector of price changes across the coupons in the coupon stack, [{tilde over (W)}] k is a matrix of relative coupon weights multiplied by a change in a benchmark rate, k is a time horizon, and {circumflex over (d)} is the vector of relative coupon durations;

calculating, by the computer system, real-time relative coupons for the coupon stack based on a real-time current coupon yield for the sector;

calculating, by the computer system, real-time relative coupon weights [W](t) at real-time t for the coupons based on the calculated real-time relative coupons;

calculating, by the computer system, real-time dollar durations for the coupons in the coupon stack based on a product of real-time relative coupon weights [W](t) and the vector {circumflex over (d)} of relative coupon durations; and

calculating, by the computer system, the hedge ratios for the one or more hedge instruments based on the real-time empirical dollar durations for the coupons,

wherein the computer system comprises one or more networked computer devices, each of the one or more computer devices comprising a processor and a memory.

2. The method of claim 1 , wherein the one or more hedge instruments comprise treasury instruments.

3. The method of claim 1 , further comprising rebalancing the portfolio based on the calculated hedge ratios.

4. A computer readable medium having stored thereon instructions which, when executed by a processor, cause the processor to:

calculate a vector of relative coupon durations for multiple different coupons in a coupon stack of a mortgage sector based on a linear system [Δ{circumflex over (p)}] k =[{tilde over (W)}] k {circumflex over (d)}, where Δ{circumflex over (p)} is a vector of price changes across the coupons in the coupon stack, [{tilde over (W)}] k is a matrix of relative coupon weights multiplied by a change in a benchmark rate, k is a time horizon, and {circumflex over (d)} is the vector of relative coupon durations;

calculate real-time relative coupons for the coupon stack based on a real-time current coupon yield for the sector;

calculate real-time relative coupon weights [W](t) at real-time t for the coupons of the coupon stack based on the real-time relative coupons;

calculate real-time dollar durations for the coupons in the coupon stack based on a product of real-time relative coupon weights [W](t) and the vector {circumflex over (d)} of relative coupon durations; and

calculate a hedge ratio for one or more hedge instruments based on the real-time dollar durations for the coupons, wherein the hedge ratios are used to hedge a portfolio of mortgage-backed securities belonging to the mortgage-backed security sector.

5. The method of claim 1 , wherein:

calculating the vector {circumflex over (d)} of relative coupon durations comprises calculating the vector {circumflex over (d)} of relative coupon durations once daily; and

calculating the real-time dollar durations comprise calculating the real-time dollar durations in real-time based on the vector {circumflex over (d)} of relative coupon durations.

6. The method of claim 5 , further comprising calculating the vector Δ{circumflex over (p)} of price changes prior to calculating the vector {circumflex over (d)} of relative coupon durations.

7. The method of claim 6 , wherein the matrix [{tilde over (W)}] k is calculated using daily changes in the benchmark rate and relative coupon weights.

8. The method of claim 7 , wherein calculating the vector {circumflex over (d)} of relative coupon durations comprises employing singular value decomposition of the matrix [{tilde over (W)}] of relative coupon weight to calculate the vector {circumflex over (d)} of relative coupon durations.

9. A computer system for computing hedge ratios for one or more hedge instruments to hedge a portfolio of mortgage-backed securities belonging to a mortgage sector, the sector having multiple different coupons in a coupon stack, the computer system comprising:

one or more computer devices, each of the one or more computer devices comprising a processor and a memory, wherein the one or more computer devices are programmed to compute the hedge ratios by:

calculating a vector of relative coupon durations for coupons in the coupon stack based on a linear system [Δ{circumflex over (p)}] k =[{tilde over (W)}] k {circumflex over (d)}, where Δ{circumflex over (p)} is a vector of price changes across the coupons in the coupon stack, [{tilde over (W)}] k is a matrix of relative coupon weights multiplied by a change in a benchmark rate, k is a time horizon, and {circumflex over (d)} is the vector of relative coupon durations;

calculating real-time relative coupons for the coupon stack based on a real-time current coupon yield for the sector;

calculating real-time relative coupon weights [W](t) at real-time t for the coupons based on the calculated real-time relative coupons;

calculating real-time dollar durations for the coupons in the coupon stack based on a product of real-time relative coupon weights [W](t) and the vector {circumflex over (d)} of relative coupon durations; and

calculating, by the computer system, the hedge ratios for the one or more hedge instruments based on the real-time empirical dollar durations for the coupons.