The MBA mortgage applications index is 1.9 percent higher in the May 17 week. It is 2.6 percent higher than four weeks ago and 1.5 percent lower than a year earlier. The purchase index is 1.2 percent lower in the current week and 2.9 percent lower than four weeks ago and 11.6 percent lower than a year earlier. The refinancing index is 7.4 percent higher and is 13.6 percent higher than four weeks ago and 21.2 percent higher than a year earlier. In the May 17 week, refinancing accounted for 34.0 percent of mortgage applications compared to 32.0 percent in the prior week. Low levels of refinancing activity mean that even a small move higher results in an outsized percentage increase. Home purchases are waiting for a dip below 7 percent for mortgage rates.

The fixed-rate mortgage index is 2.3 percent higher in the May 17 week. It is 3.9 percent higher than four weeks ago and 1.3 percent lower than this week last year. The adjustable-rate mortgage index is 3.4 percent lower and is 11.3 percent lower than four weeks ago and 3.5 percent lower than a year ago.

MBA Deputy Chief Economist Joel Kan said,"Purchase activity continues to lag despite this recent decline in rates, down 11 percent from a year ago, as potential buyers still face limited for-sale inventory and high list prices."

The contract rate for a 30-year fixed-rate mortgage is 7.01 percent in the current week. This is 7 basis points lower than the prior week, 23 basis points lower than four weeks ago, and 32 basis points higher than a year earlier. The contract rate for a 5-year adjustable-rate mortgage is 6.48 percent in the week. This is 8 basis points lower than the prior week, 16 basis points lower than four weeks ago, and 75 basis points higher than a year earlier. In the May 17 week, adjustable-rate mortgages accounted for 6.6 percent of mortgage applications compared to 7.0 percent in the prior week.

The Mortgage Bankers' Association compiles various mortgage loan indexes. The purchase applications index measures applications at mortgage lenders. This is a leading indicator for single-family home sales and housing construction.

This provides a gauge of not only the demand for housing, but economic momentum. People have to be feeling pretty comfortable and confident in their own financial position to buy a house. Furthermore, this narrow piece of data has a powerful multiplier effect through the economy, and therefore across the markets and your investments. By tracking economic data such as the Mortgage Bankers Association purchase applications, investors can gain specific investment ideas as well as broad guidance for managing a portfolio.

Each time the construction of a new home begins, it translates to more construction jobs, and income which will be pumped back into the economy. Once a home is sold, it generates revenues for the home builder and the realtor. It brings a myriad of consumption opportunities for the buyer. Refrigerators, washers, dryers and furniture are just a few items new home buyers might purchase. The economic"ripple effect" can be substantial especially when you think a hundred thousand new households around the country are doing this every month.

Since the economic backdrop is the most pervasive influence on financial markets, housing construction has a direct bearing on stocks, bonds and commodities. In a more specific sense, trends in the MBA purchase applications index carry valuable clues for the stocks of home builders, mortgage lenders and home furnishings companies.