Housing demand has been hard to forecast even as mortgage rates have declined. Just take a look at homebuilders' quarterly results so far this earnings season.

Two of America’s largest homebuilders, Lennar (LEN) and KB Home (KBH), reported third quarter net new home orders that have fallen short of Wall Street expectations.

Net new orders represent the number of new sales contracts that have been finalized and signed by buyers minus customer home order cancellations booked for the period. Investors and analysts pay close attention to this figure because its a leading indicator for homebuilders on housing activity.

Lennar, the nation’s second-largest homebuilder, said last month that its net new orders for the quarterly period ending Aug. 31 rose 4.7% from the prior year to 20,587. That fell short of analysts' forecasts of 20,827 orders, per Bloomberg data.

Homebuilder KB Home also reported in September that net orders for the period ending Aug. 31 were a disappointment. The builder said orders fell 0.4% from the prior year to 3,085, lower than analysts' estimates of 3,345 orders.

Part of the reason for the misses is that it's been hard to determine how much recent mortgage rate movements would affect buyer demand. Mortgage rates have stayed stuck between 6% and 7% this year. And in June, rates were toggling just above or below 7%.

Read more: When will mortgage rates go down? A look at 2024 and 2025.

“Maybe shame on us for not modeling it more clearly, but June and July were clearly challenging months,” John Lovallo, senior equity research analyst at UBS, told Yahoo Finance in an interview.

From a buyer's perspective, "there was uncertainty about where rates were going. There was uncertainty about where the economy and the Fed were going, and there was growing uncertainty about the election,” Lovallo added.

The uncertainty doesn't appear to be going away despite the Federal Reserve's jumbo interest rate cut in September. Mortgage rates had already been on the decline as investors had bet on a rate reduction ahead.

It's unclear how much they'll fall. Data from Freddie Mac shows the average 30-year fixed mortgage rate jumped by 20 basis points to 6.32% last week. This marks the biggest week-over-week increase since April.

Read more: Is this a good time to buy a house?

Goldman Sachs revised its year-end forecasts in early October for 30-year conforming mortgage rates, lowering them to 6% for this year and 6.05% for 2025, down from the previous estimates of 6.5% and 6.1%.

The firm's strategists said in the note that there's "limited room" for major declines. They think "the decline in mortgage rates has largely run its course."