What Causes Mortgage Rates to Change?
Mortgage rates change primarily because of movements in the bond market, especially Mortgage-Backed Securities (MBS). When investors buy MBS, prices rise and mortgage rates tend to fall. When investors sell them, prices drop and rates usually increase. These movements are influenced by factors such as inflation, Federal Reserve policy expectations, Treasury yields, and major economic reports. Because financial markets move throughout the day, mortgage rates can sometimes change multiple times in a single day.
By Rami Ameer · 2 min read
The Main Driver of Mortgage Rate Changes
Mortgage rates change because of bond market movement, especially Mortgage-Backed Securities (MBS).
When investors buy or sell MBS, their prices move, and lenders adjust mortgage rates accordingly.
Basic rule:
MBS prices go up → Mortgage rates go down
MBS prices go down → Mortgage rates go up
This happens because lenders must price loans based on what investors are willing to pay for those mortgage bonds.
Why Mortgage Rates Can Change Multiple Times Per Day
Mortgage lenders issue rate sheets every morning.
But if the bond market moves significantly during the day, lenders may issue reprices.
Example:
Time | Market Move | Result |
|---|---|---|
Morning | Stable market | Initial rate sheet released |
Midday | Bonds fall | Lenders raise rates |
Afternoon | Bonds recover | Lenders improve rates |
That’s why mortgage rates can sometimes change several times in one day.
Economic Factors That Move Mortgage Rates
Several major economic forces influence the bond market and therefore mortgage rates:
1. Inflation
High inflation is the biggest enemy of low mortgage rates.
Investors demand higher yields to offset inflation risk.
2. Federal Reserve Policy
The Fed does not directly set mortgage rates, but it strongly influences them through:
Interest rate policy
Quantitative tightening or easing
Market expectations
3. Treasury Yields
Mortgage rates tend to track the 10-year Treasury yield.
When Treasury yields rise, mortgage rates usually rise as well.
4. Economic Data
Major reports can move rates quickly:
Jobs report (Nonfarm Payrolls)
CPI inflation data
GDP
Retail sales
Strong economy → higher rates
Weak economy → lower rates
5. Global Events
Unexpected events can move markets:
Banking crises
Wars
Recessions
Stock market volatility
Sometimes these events cause investors to move money into bonds, which lowers mortgage rates.
The Key Takeaway
Mortgage rates don’t move randomly.
They are mainly determined by:
Mortgage-Backed Securities (MBS) prices
Inflation expectations
Federal Reserve policy signals
Treasury yields
Major economic reports
Because financial markets change constantly, mortgage rates can move daily and sometimes multiple times per day.