A graduated annuity is like a regular annuity, except instead of getting the same cash flow each period, the cash flow grows at a given rate throughout the term. There a two basic types of graduated annuities, ordinary annuities (cash flow comes at the end of each period), and annuities due (cash flow starts at the beginning of each […]

## Mortgage Pool – Holding Period Return

This spreadsheet was originally compiled to help make the decision to either sell mortgages that were originated, or keep them. It can also be used to help with the decision to purchase a pool of whole loans, or a securitized mortgage pools. Two different concepts of return are referred to in this post. The two are […]

## Prepayment Penalty

Once upon a time (all my numbers and loans are fictitious) the loan department was negotiating the sale of a parking lot. It seemed that the buyer and we were at a stalemate. We wanted \$5,700,000 for the lot and the buyer was only willing to pay \$5,500,000. The market rate for this type of loan was […]

## Defeasance

Important This post and spreadsheet has been updated. Please click this link to Defeasance 4.0 If you are involved in commercial lending or perhaps municipal bonds you are probably familiar with the term defeasance. Commercial loans normally have hefty prepayment penalties, while some loan documents prohibit prepayment altogether. Commercial loan defeasance is a collateral substitution […]

## Skip-a-Payment

Around this time of year, banks and credit unions will sometimes offer borrowers the option to skip a payment or two in return for a fee. This offering is a spreadsheet that calculates the APR on a loan after the borrower accepts the offer to skip one or more payments. There are two amortization schedules […]

## Simple Formula for Converting Compound Interest Rates

This workbook has a simple formula to convert compound interest rates. =IF(t>500,f*LN(1+g/f),IF(f>=500,t*(EXP(g/t)-1),(t*((1+g/f)^(f/t))-t)))  Where: g = Current interest rate f = Number of times the current rate compounds per year t = Number of times the converted new rate compounds per year This lookup table grabs two of the numbers for the formula Continuous compounding in Excel […]

## Mortgage Backed Securities (MBS) “MegaFormula”

See updated formula at: MBS Math Formula. Servicing, CPR, Payment Delay, Default Rate & Loss Severity http://pistulka.com/Other/?p=2384 This post is just to show you 20-somethings what we had to go through to calculate the price of a mortgage backed security back in the day. I had the first desktop computer (before Apple and Radio Shack were […]

## PSA vs. CPR

The workbook for this post has been replaced with a workbook with two separate sheets.   In past posts I showed you how to calculate a Constant Prepayment Rate (CPR) with an amortization schedule. This post will allow you to compare a CPR rate to a model provided by the Public Securities Association (PSA). PSA […]

## Bonus Checking

To understand this next spreadsheet, you have to take your accounting hat off and put your financing hat on. Consider all your sources of funding; savings accounts, money market accounts, CDs, borrowing, and checking accounts. There may be more, but considering the above, checking accounts will always be the cheapest source of funds. The reason […]

## APR – Fixed Rate Mortgage

Given the inputs in yellow cells, check boxes and option buttons, this sheet uses an amortization schedule to calculate APR (or APY) for a fixed rate mortgage. Both Loan Balance and Interest Rate need no explanations. Truth in Lending Fees are additional dollar costs to the borrower to acquire the loan. Points represent a percent of […]

## PV and FV of Periodic Cash Flows

I thought I had already posted this spreadsheet, but it looks like I missed it. The sheet uses both formulas and Excel functions to calculate the present value, future value and also shows how to calculate the APR and APY on a cash flow, give either the present or future value. This sheet is very […]

## Macaulay Duration of an Amortizing Loan

The term “duration” is often used interchangeably by market participants to denote either a volatility measurement, a weighted term to maturity, or a portfolio risk measurement. In practice there is more than one definition of duration. The following describes the most basic duration along with it’s calculations. In a future posts we will discuss Modified Duration, Effective Duration, […]

## Valuing Servicing Matrix

On August 26, 2014 I showed  an amortization schedule that could be used for initially valuing servicing. I introduced the use of constant prepayment rates (CPR) in order to get a more realistic pricing than assuming the pool of mortgages or commercial loans would never prepay. Considering the ease of refinancing and the mobility of the labor […]

## Annuity

There is nothing special about this annuity calculator except: All input is with sliders Each line of the results are one cell text and formulas The dollar growth and payout balances are charted You can pick from monthly deposits or lump sum deposit Inputs: Outputs:   Download workbook “Annuity” from: http://www.pistulka.com/Excel_Shared/  Downloads Written in Excel […]

## Two Mortgage Payoff Tables

Assuming you don’t have a balloon payment on your fixed rate 30-year mortgage, these two tables may be helpful. Table1 will tell you when your mortgage will be paid off, given making extra payments each month. Table2 is the reverse of Table1, in that you give it the number of years you want to have […]