Spurred by the Federal Reserve's announcement that it would not raise interest rates this year and that it would start buying bonds again, the average rate on the 30-year fixed mortgage is falling.

Rates are falling due to the Federal Reserve's announcement and big picture reassessments of the lack of global economic growth, as investors head back into the bond market.

Mortgage rates loosely follow the yield on the 10-year Treasury bond.

The average rate on a 30 year fixed mortgage jumped to over 5 percent last November, but has fallen since.

Mortgage rates were lower in 2016 and 2017, which helped cause a surge in home values during those years. Buyers could afford to pay more with interest rates in the 3.5 percent range.

The supply of homes for sale was also incredibly low, prompting more bidding wars.

With economic growth in the U.S. in question and global growth clearly shrinking, interest rates could possibly move even lower than they are now. Or not.