Banking sector fears were responsible for a nice little drop in mortgage rates over the past 2 weeks.  As those fears subside (to some extent, anyway), the market reaction has reversed to some extent.  This is most noticeable in the stock market in the US.

Stocks don't dictate interest rates.  That job falls to bonds and bonds have been slower to retrace their recent steps.  That means rates are higher, but not yet back up to the levels seen before the banking drama began.  That's a good thing, but it also presents a vulnerability. Specifically, if banking fears continue dying down, rates have more room to rise.  

Another key input for rate momentum will be tomorrow's Fed announcement.  The Fed is highly likely to raise rates by 0.25%.  There's a small chance (very small) they abstain on a hike at this meeting.  Either way, they will also be updating their rate outlook for the coming months/years and that's arguably even more important than what they do with tomorrow's rate hike.  

Last but not least, Fed Chair Powell will hold the normal post-announcement press conference and that will give him a chance to balance out whatever decision is made on the rate hike.  In other words, if they don't hike, Powell could speak more cautiously about the rate environment.  If they do hike, he could offer reassurances that they're not trying to precipitate any more banking issues.  

Rates could be rising or falling fairly abruptly starting after 2pm Eastern time tomorrow as a result.