“Local brokerages had alluded to the fact that about one-quarter of their deals were private, but until we had the data to corroborate this it was purely anecdotal,” said PocketList’s Tom MacLeod. “We feel like we’re shedding light on a $2 billion ‘hidden’ market that most people don’t know exists.”

The real estate tech startup contends that this is the first official accounting of the local private sales market, which until now had only been estimated.

Private home sales accounted for 24 percent of San Francisco sales in 2014 and 23 percent of sales in 2015, according to a study by PocketList

358 San Carlos is a four-bedroom Victorian in the Mission that sold on the private market for $2.6 million.

358 San Carlos is a four-bedroom Victorian in the Mission that sold on the private market for $2.6 million.

The open kitchen-dining area for 350 Eureka, which sold on the private market for $2.4 million at the end of 2015.

The open kitchen-dining area for 350 Eureka, which sold on the private market for $2.4 million at the end of 2015.

The study was based on a review of data from the City Assessor’s office (through November 6, 2015) as well as the San Francisco Association of Realtor’s Multiple Listing Service. Other data gleaned from the survey indicated that private sales tend to be higher during the first quarter of the year, with about 30percent of 2015’s private transactions conducted in January and February.

MacLeod explained that many sellers go the private sale route to test the market before going on the MLS. But because the market in San Francisco is so hot, they often end up getting great offers during this pre-market period and decide to make a deal without the headaches of staging and open houses.

“This also explains why private sales are more popular in the first few months of the year, as homes that would otherwise go to the public market in the spring are being snatched up by savvy buyers in the pre-market period,” he said.