Disclaimer: I am not an lawyer, and offer this spreadsheet free with no guarantees either written or implied, as to the appropriate use of this spreadsheet, or its accuracy. I am not recommending this spreadsheet to be used for any particular state or municipality.     Let us assume that you live in a state […]

Note: I have updated this post and spreadsheet with another way to create your own CPR vectors: Annual CPR Vectors Previously, I showed a way to vary the CPR prepayment rates http://pistulka.com/Other/?p=1300 on an amortization schedule. That method did not include ramps. This spreadsheet shows how to ramp CPRs up, down, and flat. In this […]

HEL (Home Equity Prepayment) is similar to the PSA prepayment model in that it starts a 2% CPR in the first month and increasing at 2% CPR until month 10. It then remains at 20% CPR for the remaining life of the pool. Increases or decreases to the standard 100 HEL are made the same […]

I have to admit that I have never purchased or sold manufactured housing loan pools, but am aware that those that do own or trade these pools, have different assumptions when applying prepayment rates. The MHP calculation is very close the PSA ramp, except that the first month starts with a 3.7 CPR, and each […]

In the previous spreadsheet used to calculate historic CPR and PSA, I used a separate sheet in the workbook to run an iteration on an amortization schedule in order to calculate PSA. An iteration is only necessary if the loan pools are 29 months old or less. I have replaced the amortization sheet with a […]

A reader asked if I had an example of a CMO Inverse IO, and I did not. Although I have not had access to a Bloomberg to check my assumption, I thought I would give it a try. Actual IO’s may vary from my example, but I think I have captured the essences of an […]

This is my fourth free CMO Excel spreadsheet. This post is going to be very short. You can find a lot of information online, so I am not going to add much. After entering the information on the “Inputs” sheet (yellow cells only), go to the “IO_PO” sheet where you will find ways of analyzing […]

I have posted two other examples (and Excel workbooks) of CMO structures in the past.  Floater & Inverse-Floater CMO and Sequential Pay CMO. Now, we are going to look at a CMO PAC (Planned Amortization Class). It is a simple example, with only two tranches, the PAC and Companion (or sometimes called Support) bonds. The PAC […]

Not all banks treat leap years the same, when calculating interest on deposits. Many financial institutions use basically the same method (or a close variation) I used in this formula. Check with your bank before relying on this method. The method I am referring to is: Interest is compounded daily. The balance on any given […]

My first post on this blog was in August of 2014 and it was called: No XNFV Excel Function? The idea was a formula for calculating future value with dates. There was a XNPV function for present value, but no function for future value. My formula looks like this: =SUMPRODUCT((1+APY)^((MAX(Dates)-Dates)/365)*Data) Of course there are other workarounds, […]

I have posted previous calculations of effective duration and convexity for a pool of mortgage loans, however past spreadsheets required three amortization schedules, on separate sheets. Using the mega formula for pricing, this spreadsheet (in my opinion) is cleaner and easier to understand. Effective duration is used to analyze mortgage pools, rather then Macaulay or […]

Before I added default and loss severity to the mega formula for the price of a mortgage pool, I produced a price/yield table. That old post was http://pistulka.com/Other/?p=707.  This post and Excel workbook includes the added variables. As is true with all of my spreadsheets, only the yellow cells are input cells:    * Servicing – […]

In May of 2015 I published a post called “3 -Ways to Bootstrap Spot Rates for the Treasury Yield Curve”. There was also an Excel workbook linked to that post. The workbook link is: http://pistulka.com/Excel_Shared/3_Spot_Rates.xlsm Rather than posting a new workbook, I am leaving the old workbook, but I added a new sheet called “Fourth Method”. […]

I have to be honest. I had never heard of a flat rate loan, until Rishi asked me to create an Excel spreadsheet for one. According to Wikipedia, flat rate loans are: “Loans with interest quoted using a flat rate originated before currency was invented and continued to feature regularly up to and beyond the […]

This is my third post on RMD, thus the 3 point 0. The other two post are: http://pistulka.com/Other/?p=2422 http://pistulka.com/Other/?p=2674 Read my first post if you are not familiar with RMD. This Excel workbook came about at the request of a reader who’s firm manages hundreds of retirement plans. I put together a spreadsheet to calculate […]