"There is more confidence in the economy, and people have more money to spend," Pruner said.
A 12-bedroom waterfront estate on 50 acres sold for $120 million this month in what the listing and selling agent, David Ogilvy, has called the most ever paid for a residential property in the United States. That was quickly followed by a $14.3 million sale Monday of a 52-acre estate in nearby New Canaan.
Those two sales within a week are "quite amazing," said Barbara Cleary, whose real estate company sold the New Canaan property after listing it for about five years.
"I think there is new interest in investing in real estate," Cleary said. "I think the higher end is getting more activity."
The New Canaan property had been owned by reclusive copper heiress Huguette Clark, who died in 2011. She bought it in 1951 but never moved in, Cleary said.
"This was really sort of the crown jewel of the town," Cleary said.
The property was originally listed by another broker for $34 million, Cleary said.
Buyers were not disclosed.
Pruner speculated that some sales could stem from buyers' concerns about taxes in New York City. In testimony to Connecticut lawmakers about legislation concerning estate and gift taxes, Pruner said only three houses sold in Greenwich for more than $10 million in the first seven months of last year but eight sold starting in August, around the time recently elected Mayor Bill de Blasio became the leading candidate on a platform of higher taxes on those earning more than $500,000.
De Blasio spokesman Wiley Norvell said that was "ridiculous" and there was "zero evidence to support that speculation."
The Democratic mayor proposed universal pre-kindergarten funded with a tax hike on the wealthy, a plan that was defeated. The program will instead be funded with money from the state budget.
The home sales are good for Connecticut because they show wealthy buyers want to live in the state, and they are major contributors to taxes, charities and business startups, Pruner said.
While sales of homes above $10 million rose, sales between $5 million and $10 million in Greenwich fell from last year, Pruner said. There were five such sales in the first quarter of this year, down from 15 in the same period last year, he said.
Associated Press writer Deepti Hajela contributed to this report from New York.