Archive for the ‘"PAY MORTGAGE OR INVEST"’ Category


February 10, 2010

I have read a lot of subjective articles and on the issue, so I have decided to do the math.  Paying down my s mortgage is a safe way for me to diversify my retirement investments.  I also believe that investing in the stock market is an important part of my overall strategy, but paying down my mortgage ensures that I am not putting all my eggs in one (risky) basket.

The easiest way to invest in the S&P 500 is to purchase shares of SPY.  SPY is a high-volume Exchanged Trade Fund (ETF) whose  inception date was January 29th, 1993.   SPY seeks to correspond generally to the price and yield performance, before fees and expenses, of the S&P 500 Index.

Simulation Information

To keep it simple, I have chosen to ignore trading fees but consider SPY’s average 2.5% dividends.

Start Date: 01/29/1993 (spy’s first trading day)

End Date: 02/23/2010

Number of trading years: 17

Dividends:  Every 12 months, my simulation deposited 2.5% of the market value into the account.

Monthly deposit into simulation trading account = $300  (I deposited $300 on 01/29/1993 and $300 on the first of every month from there on.  I kept my monthly contributions at $300 for the entire 17 years of simulation.  I kept it at a fixed investment amount because mortgage rates are also fixed.)


Total Invested = $61,800

Total # shares purchased during the 17 years of simulation = 914

Current account value at $110.67 per share (that was SPY’s closing price on 02/25/2010 when I ran my simulation) = $100,414.98

Total return in 17 years = $38,614.98.   That’s a a total return of 62.48% in 17 years.

We would be in bad shape because it’s an average of 3.7% return per year.  At3.7% return average per year, our gains would have been outpaced by inflation whose rate is substantially higher than 3.7% per year.


Now let’s assume that we got a 30-year, fixed-rate mortgage at the very low rate of 5% 17 years ago (that rate did not exist back then).  Let’s borrow $100,000.  During the 17 years, we would have paid only paid the minimal payments.  The $300 extra money we had each month was used in the stock market while we only made the minimal payment of $536  (principal + interest).  After 17 years, we would still have 13 years left in our mortgage.   We would still have an unpaid balance of $61,487 left.

Now let’s go back in time and, instead of investing the $300 a month in the stock market, let’s apply it to our mortgage principal.  WE WOULD HAVE PAID IT OFF IN 2006.

But back in 1993, our mortgage rate would be 7%.  At 7%, the numbers look astronomical.  For our 30-year mortgage, if we paid only the minimal payment while investing our extra $300 a month, we would pay a total of $139,508 in interest in the life of the loan.  If we apply our $300 extra money towards our principal, we would again have paid off our mortgage in 2006.

So, the property that we purchased 17 years ago for $100,000 would be worth how much today, 17 years later.  (In my case, I know that the house that I purchased back in 1998 (that’s not even 17 years ago) is worth tens of thousands more today.)

Real estate as an investment

If you Google “housing prices chart,” you come across a site called  (I AM NOT AFFILIATED WITH THEM.)  And here’s their chart showing the historical housing prices in the United States.  You can see that real estate has been a solid investment vehicle even considering the recent drop in prices.  Our $100,000 property which we purchased 17 years ago would be worth substantially more today.