In May, sales of previously-owned homes slumped, the second month in a row of declining sales. The National Association of Realtors, which tracks those sales, pointed to the same culprit it’s blamed for the past few years: not enough supply of homes to buy.

Shortly after the Realtors released their data, Regions Chief Economist Richard Moody wrote this in a research note: “Given that we see little reason to expect meaningful relief on the inventory front over coming quarters, we think it reasonable to conclude that we have passed the cyclical peak for existing home sales.”

Ten years after the financial crisis, the notion of a housing “peak” – which would naturally be followed by a downturn – seems downright spooky. The trauma of the last correction is still with us: more than 1.1 million Americans are still underwater, according to Black Knight, many foreclosures are still wending their way through the system, and ultra-tight lending standards put in place when the pendulum swung hard after the correction continue to lock many Americans out of the market.

But under normal circumstances, a correction in housing, like in any market, is normal, foreseeable – and possibly, though not certainly – upon us.

(It’s also worth noting that many voices have spent the last several years, seemingly ever since the last bubble burst, squawking about a new bubble. And it’s true that prices in many metros keep pushing higher and higher, defying the laws of logical market dynamics. But that’s been driven by outsize demand and lean supply that can’t keep up, not speculation.)

Also read:Bubble-era home buyers jumped at rising prices; today, they’re turned off

For the handful of economists calling the present moment a cycle top, it simply means that from here on, sales will stop growing, and possibly even decline, as will home prices.

Here’s how Nationwide Chief Economist David Berson put it in May, in response to the Realtors’ April sales figures: “We project that existing home sales will edge up by around 1% in 2018 to around 5.56 million units, which would be the strongest pace of sales since 2006. We expect that this will be the high-water mark for sales in this cycle.”

There’s widespread agreement among housing-watchers that the biggest problem facing the market is the supply-demand imbalance referenced in the May existing-home sales data.

Related story: Why aren’t there enough houses to buy?

Where analysts disagree is on what impact that will have. Moody and another economist, Ian Shepherdson of Pantheon Macro, believe that if supply remains stifled, it will continue to push home prices higher and higher. Add that to rising mortgage rates, and at some point demand will wane.

“You can withstand some further increase in mortgage rates, but at some point, eventually you hit a tipping point on mortgage rates where it does erode affordability,” Moody told MarketWatch.

Read: Housing’s big question — what will happen when buyers think 4% rates are ‘crazy’

But Sam Khater, chief economist for mortgage finance provider Freddie Mac, thinks there’s still room to run. Khater thinks existing-home sales have “hit the speed limit,” and recognizes that rising rates will at some point price many people out of the market.

Still, he said, “Total sales should continue to go up.”

Usually, over-supply is what causes a housing downturn, Khater said. Remember home builders throwing up development after development in 2005-2006, farther and farther away from city centers, in the expectation that there would be an endless supply of people to buy them?

“Here we are nine years in, we’ve had three straight years of inventory decline,” Khater said in an interview. “It’s not only not-expanding, it’s contracting. The consensus is that if there’s a recession, it’s a modest, plain-vanilla recession. If that’s the case, I think what it might do is cause inventories to rise modestly and home price growth to slow. My base case is that – an economic recession but not a real estate recession.”

For economic history wonks, Khater likens his “base case” to the 2000-2001 downturn, which was a recession caused in part by the implosion of the dot-com sector – but which didn’t really hit the housing market.

Khater is reluctant to forecast details about something he thinks won’t happen for another two years or so, but he did point out that markets that are the most overvalued would likely be the ones that get hurt the most in any kind of downturn.

Read: Pending-home sales slide to a 4-month low as supply dries up

Picture a mild economic downturn, in which hundreds of tech workers along the West Coast lose their jobs. Many would be unable to make their mortgage payments, or might decide to take a different job in a different city. That would prompt many people to sell their homes at cheaper prices than the houses might be valued at if the economy wasn’t under pressure. At the same time, there would be less of the frenzied demand for homes that bid prices higher. (As Khater emphasizes, it’s impossible to know which sectors of the economy get hurt the hardest in the next downturn, and it’s possible the pain could be widespread, nationwide.)

In Richard Moody’s outlook, a housing downturn before we get to an economic downturn, demand would “settle back,” as he puts it, and “that would be reflected in less upward pressure on prices.”

That is to say, prices across the country could even continue rising – just more slowly.

That’s what happened in Houston when oil prices collapsed in 2014. Yearly home price gains decelerated from 12% to 4%, Khater noted, “but never went negative, and the impact on performance was fairly minor.”

That is, people were able to continue to make their mortgage payments on time.

There are, again, lots of caveats. In a nationwide recession, some areas that aren’t as hot as Houston (over 104,000 out-of-state residents re-located there in 2016) won’t fare as well.

Still, homeowners generally have built up more equity than at any time in American history, and they’re staying in homes longer. That should provide a good “cushion” for most homeowners in a downturn, as Khater puts it.

Put another way: the most vulnerable homeowners in the next downturn could be people in pricey coastal markets who bought recently and have very little equity in their homes, either because they made small down payments or because they’ve taken it out.