The Amazon Spheres in downtown Seattle, with construction cranes in the distance. (GeekWire Photo / Kurt Schlosser)

Seattle home prices have been soaring for years, pitting buyers against each other in fierce competition as the city’s tech boom drove the housing market to seemingly limitless heights. But new data show the market cooling slightly, an indication that a limit does, in fact, exist — and Seattle might hit it sooner than expected.

That’s according to Redfin, which published a blog post Wednesday making the case that Amazon’s plans to open a second headquarters in another city could “quickly turn Seattle into a buyer’s market.”

The post, by Redfin housing market analyst Tim Ellis, envisions two scenarios in which Amazon slows hiring in Seattle and transfers employees to HQ2, as the company’s remarkable second headquarters project is known. (Ellis separately runs the independent Seattle Bubble blog and writes freelance pieces for GeekWire.)

On the extreme end of the spectrum, Redfin estimates that new home sale listings could jump to their highest levels since 2009 if Amazon were to drastically slow hiring in its hometown as Seattle employees migrate to HQ2.

Even Redfin’s more cautious analysis — in which Amazon slows hiring less dramatically and fewer Seattle employees move to HQ2 — the market is still likely to flip even more in buyers’ favor.

That shift has already begun. The average home in Seattle is selling for slightly below its listing price for the first time in four years. Overall, listing prices have dropped about 7 percent since the spring and they are declining faster than anywhere else in the nation.

Redfin agent Jessie Culbert told Ellis that the Seattle housing market is already seeing the effects of HQ2, with buyers “waiting on the sidelines for the announcement of where HQ2 will be located.”

Amazon will unveil the city selected for its second headquarters by the end of the year. The company plans to hire up to 50,000 employees at its second headquarters, slightly more than the estimated 45,000 in Seattle. Although Amazon has not said it plans to slow growth in Seattle, many speculate that Amazon will shift much of its growth to HQ2.

Read the full Redfin analysis here.

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