After a scorching four years, the luxury real-estate market may be cooling off.
Sales of homes for $1 million or more fell 20 percent in the fourth quarter compared with those in the third quarter and posted their worst year-on-year growth since 2011, according to the CNBC Luxury Real-Estate Report, conducted by Redfin, a real-estate brokerage and research firm.
There were 14,834 homes sold for $1 million or more in the major markets covered by Redfin. That was down from the 18,435 million-dollar homes sold in the third quarter and up only slightly from the 13,589 homes sold in the fourth quarter of 2013.
Sales of homes priced at $5 million or more were also weak, falling 10 percent in the quarter.
"We're seeing sales of luxury homes continue to taper," said Nela Richardson, chief economist at Redfin. "The top of the market is losing steam."
Of course, weakness is all relative in the luxury housing market. Prices continued to climb for high-end homes, with prices up 2 percent year over year, to an average of $1.79 million. And inventory fell in the fourth quarter, with the number of million-dollar-plus homes for sale falling 23 percent in the quarter.
But inventory is up compared with the fourth quarter of 2013. (RedFin's data covers more than 100 markets, but doesn't include New York City, though sales volume in Manhattan fell 18 percent in the fourth quarter compared with that in the third quarter, and declined 17 percent year over year, according to Douglas Elliman Real Estate).
It's unclear whether the fourth-quarter slowdown is a one-off or a signal of a broader shift in the housing market. Since the housing crash, luxury homes have recovered far more quickly than the broader housing market, as the wealthy have recouped their fortunes faster than the rest of America.
Yet Richardson said the housing market may be entering a new phase, where the top slows down and the broader housing market climbs back.
"2015 is kicking off with a market that's starting to look more balanced," she said. "Both luxury sales growth and luxury inventory growth are slowing down, even as sales and supply are picking up in the market overall. Things are about to get bumpier for the 2015 luxury market as rates will eventually rise, the stock market is becoming more volatile, global demand is waning and gas prices are falling."
While volatile stock markets may be spooking American buyers, weakness in China, Russia and Latin America could be hurting demand from foreign buyers. Overseas buyers have been crucial to sales of high-end homes in major cities such as Miami.
The stronger dollar has also hurt overseas demand, as U.S. homes become expensive for those buying with other currencies.
The most expensive home deal in the fourth quarter was the $70 million sale of the 23,000-square-foot ultra-modern home in Beverly Hills, California, sold to Markus "Notch" Persson, the founder of the Minecraft video game. The house, built on spec by handbag magnate Bruce Makowsky, was listed for $85 million.
Outside of New York, the community with the largest number of $1 million-plus homes sold in the quarter was Manhattan Beach, California, with 109 sales. Laguna Beach, California, was second, with 91.
Among the biggest discounts in the quarter was the $5 million sale of a waterfront property in Newport, Rhode Island, that had once been listed for $12.9 million. A property in Santa Paula, California, listed for $6.34 million ended up selling for $3.5 million.
This article originally appeared in CNBC.