Jerome Powell is the Chair of the Federal Reserve--the entity that sets overnight lending rates in an attempt to keep inflation in a low, stable range. Inflation has been anything but low and stable recently, so the Fed has hiked overnight rates at the fastest pace in 40 years.
Mortgage rates have also risen at the fastest pace in 40 years, but they are not directly dictated by the Fed. Rather, the Fed's direct influence on overnight rates spills over to the rest of the rate market. The longer the duration of any given borrowing term, the less connected the interest rate may be to the Fed Funds Rate.
Moreover, the market adjusts expectations for the Fed Funds Rate constantly whereas the Fed only officially hikes/cuts 8 times a year. When the Fed meets again in 2 weeks, they will certainly be hiking rates again. The only question is "by how much?"
Markets had been steadfast in their expectations for a 0.25% hike, which is viewed as the minimum increment for a rate change from the Fed. With some recent data indicating plenty of economic resilience and persistent inflationary pressures, calls have increased for a 0.50% hike.
In a scheduled testimony before the Senate Banking Committee today, Fed Chair Powell stopped short of specifying a number for the next rate hike, but commented qualitatively on the need to hike faster/more than previously expected. Markets consequently upped the odds for a bigger hike in 2 weeks as well as a higher ceiling expected by the end of 2023.
Again, the Fed Funds Rate doesn't directly dictate mortgage rates, but there was a bit of spillover as market expectations shifted in the direction of "higher for longer." The average mortgage lender was already close to 7% for a top tier conventional conforming 30yr fixed scenario, and today's weakness was enough to officially push us up into the low 7's.
As Powell reminded senators, the Fed will make its decisions based on data, and there's important data left to come between now and Fed day. This is a double-edged sword as stronger data could send rates even higher just as easily as weaker data could help us get back below 7%.
The reports with the biggest potential to cause volatility (for better or worse) are Friday's jobs report and next Tuesday's Consumer Price Index (CPI).