The number of pending sales of existing homes rose 0.8% in February, according to the National Association of Realtors; they were down 21% from a year ago. That marks the third-straight month pending sales have been up, and it may be puzzling, given interest rates are still on the rise.

“We’ve had much higher interest rates, and because we’ve had a depletion in some quarters of pandemic-related saving, money for down payments is not as readily available as it once was,” said Carl Tannenbaum, chief economist at Northern Trust.

Now, pending home sales are not done deals — the paperwork has started, but the sale probably won’t close for a month or two. More housing paperwork in February is a sign of something that happened a month or two earlier.

“The main reason was lower mortgage rates we had during December and January,” said Nadia Evangelou, senior economist for the National Association of Realtors. 

Mortgage rates also dipped between January and early February, from 6.5% to 6.1%. That was enough for tens of thousands of homebuyers to pounce. And the fact that so many homebuyers lunged at the opportunity is a sign of how stressed they are, said Danielle Hale, chief economist at Realtor.com. 

“A lot of home shoppers are at the edge of their budget range, and when mortgage rates come down, that creates a little more breathing room,” she said.

But, of course, mortgage rates didn’t stay down; they ticked back up in February, then started to tick back down this month. A bumpy ride for mortgage rates means a bumpy ride for home sales.

“If mortgage rates rise from here, then home sales will continue to be very slow and housing activity will be very slow,” said Igor Popov, chief economist at Apartment List. “But if mortgage rates continue to fall, then we might see that a lot of these potential buyers on the sidelines start to get out there and buy homes.”

And what will happen to mortgage rates has a lot to do with what the Federal Reserve does with interest rates. Surveys from the New York Fed show that Americans expect mortgages to hit about 8% a year from now.