SOFR - Secured Overnight Financing Rate is designed as a replacement for LIBOR, which is being retired as a financial index in 2021. Below, we display both current SOFR rates and historical values for SOFR for a range of time periods.
What is SOFR?
SOFR is a broad measure of the cost of borrowing cash overnight collateralized by Treasury securities; values are published by the Federal Reserve Bank of New York.
SOFR Rates
Like LIBOR, SOFR comes in a number of time periods -- an overnight rate and rates that are an average of the previous 30, 90 or 180 days. These longer-period SOFRs are compounded averages of the SOFR over rolling 30-, 90-, and 180-calendar day periods. There is also a base-line index (the "SOFR Index") that can be used to calculate values for custom time periods. This "SOFR Index" measures the cumulative impact of compounding the SOFR on a unit of investment over time, with the initial value set to 1.00000000 on April 2, 2018, the first value date of the SOFR. The SOFR Index value reflects the effect of compounding the SOFR each business day and allows the calculation of compounded SOFR averages over custom time periods.
SOFR is a new index, made officially available starting in March 2020, so there is no lengthy history against which to compare it to the performance of LIBOR or any other available index. Also, although SOFR is a daily index series, HSH.com will be providing the data each Tuesday morning covering the previous five days' worth of values.
Although ARMs tied to SOFR could have any adjustment period, the standard offerings from Fannie Mae and Freddie Mac will be hybrid ARMs that adjust every six months after an initial fixed-rate period of 3-, 5-, 7 or 10 years.
SOFR-based ARMs eligible to be sold to Fannie and Freddie will use the 30-day average of SOFR as a basis for regular interest rate adjustments. However, most ARMs are not sold to Fannie Mae or Freddie Mac, and lenders are free to use other published values of the index such as the 90 day or 180 day versions, and lenders or investors can also create a "custom" SOFR of any time period to suit their needs based on the "SOFR Index" described above.
SOFR ARM Margins
To the SOFR value being used, the lender will add a markup, called a "margin", and the sum of the two becomes your loan's new interest rate. The margin called for in mortgages sold to Fannie Mae or Freddie Mac can be up to 300 basis points; as such, if the index value was 1 percent (100 basis points), the lender would add 300 basis points to it, and your loan's new interest rate would be 4 percent until the next rate adjustment occurs. For loans not sold to Fannie or Freddie, lenders are free to set their own margins and their own adjustment periods.
SOFR ARM Caps
Like other ARMs, SOFR ARMs will also have limiters on how much the interest rate can change at the first adjustment, at each subsequent adjustment and over the life of the loan. These are called "initial", "periodic" and "lifetime" caps.
For SOFR ARMs eligible to be sold the GSEs, those with fixed rate periods of 3 or 5 years have an initial cap that is 2 percentage points (above or below) the original fixed interest rate, followed by a change not more than 1 percent at each six month interval, and the interest rate can never be more than 5 percentage points above the initial rate on the loan (called "2%/1%/5%" caps). For SOFR ARMs with initial fixed-rate periods of 7 or 10 years, the initial cap is 5%, followed by a 1% periodic cap and a 5% lifetime cap ("5%/1%/5%" caps). As such, the initial interest rate could rise all the way to the maximum possible interest rate at the first rate adjustment.
Learn more about how ARMs work.
Although only available in monthly values, indexes comparable to SOFR include the Federal Cost of Funds and possibly the MTA - Moving Treasury Average (sometimes called MAT or 12-MAT).
See a comparison of the One-year Treasury, 30-day SOFR and the MTA and learn more about how they move -- and how it can affect your ARM's interest rate.