Be a Quant

How’s the market doing?” is a question that is harder to answer than it seems. A broker with unattended open houses may be bearish; a seller fielding offers the same day is brimming with optimism. Limited viewpoints, small sample sizes, old saws, and dated information often lead to misconceptions.

Noah Rosenblatt—the broker behind the popular UrbanDigs blog—is looking to change that. At its relaunch, scheduled for this week, will be devoted to data analysis, allowing users, for $20 per month, to track market shifts by neighborhood and price in real time, create trend charts, and chat about what they’re seeing. You can (to give a simple example) keep a daily watch on the inventory of listings in your area, and compare the trend with previous years or other parts of the city. If you spot a sharp change, you can adjust your price or schedule an open house immediately. You can break down data in dozens of other ways, too. Instead of waiting for quarterly reports from the brokerages, you can generate up-to-the-minute ones. It’s definitely for the hard-core numbers geek, and its data-heavy approach may intimidate the casual shopper. If, however, you are the sort of person who builds spreadsheets to track your retirement portfolio, you are likely to fall for this site, especially if you use it along with a more listings-driven service like It gives any buyer the tools to become a real-estate quant.

A test search showed a post–Labor Day spike of new listings—93, as of last Wednesday—and a small bump in contracts signed. “Manhattan is segmented. It’s not one market,” Rosenblatt says. “I wanted users to be able to see what was going on in their submarkets.” The system is linked to the city deeds registry and the database agents use. Data are scrubbed to get rid of duplicate and obsolete listings. (Cleverly, Rosenblatt sorts apartments not by bedroom count but by bathroom count, because nobody can fudge that number.)

A Rosenblatt client, appropriately named John Walkup, beta-tested the system late this winter, after he and his wife lost two Upper East Side bidding wars. “Anecdotally, the market seemed like it had collapsed, and we thought no one was going to bid against us,” he says. But they saw the tides turning (as the charts on this page show, the market was in a run-up at the time), so when they found another place, they raced “to get the deal done at our price as fast as we could.” is entering an increasingly crowded analytics field, dominated by four sites:,, and, plus the city’s ACRIS database. (Rosenblatt’s niche looks to be a focus less on individual listings and more on graphing and trend-spotting.) PropertyShark’s Matthew Haines says consumers have developed a “trust but verify” approach that has them relying on brokers but gathering facts themselves. Adds Walkup, who sifted through about 100 apartments before finally buying: “If you want to have control in the process, you have to put yourself out there.”

What The Data Reveal: A Very Cool Summer
Conventional wisdom has it that the market is in a general recovery, but these data from paint a less rosy picture of the two months just past. Data from two economically disparate neighborhoods (we chose East Harlem and the Upper West Side, but others showed similar trends) reveal that the run-up of spring 2010 stalled at the start of the summer. A year-over-year comparison (inset) reveals that the decline is much steeper than in the previous two summers, so it’s not just the usual July-August doldrums. Only one tiny bright spot: A close-in look at pending sales in September (not shown) revealed an uptick just this past week, suggesting that the swoon may have reached its nadir. Watch that figure closely in your neighborhood of choice these next few weeks— it’s a significant indicator.

Be a Quant