Will Amazon make HQ2 finalists prime housing markets?

Local real estate markets have been in flux ever since Amazon announced the 20 finalist cities vying to be the site of digital retailer's HQ2 second quarters.

The immediate home price increases have come at the hands of speculators trying to get in on the ground floor and crowding out would-be buyers looking to put down more permanent roots.

Seattle, Amazon's current headquarters, is one of the hottest housing markets in the nation and the company's success is one of the contributing factors.

The third-quarter median sales price in Seattle was $598,000, up 23.3% over the same period in 2016, according to Attom Data Solutions.

"Of course, Seattle's tremendous growth and some of the tensions it has created can't all be laid at Amazon's doors alone," said Zillow Senior Economist Aaron Terrazas in a statement. "The jobs boom around Amazon's Seattle headquarters explains less than one-fifth of the region's rising rents, with the company's growth creating an industry ecosystem that attracts many other employers to the region, which we expect to also happen in and around whichever of these 20 notable cities is chosen. The top 20 list is a mix of well-established and up-and-coming cities."

Affordability is already at the breaking point in at least half of these cities, according to CoreLogic.

And then add in rising interest rates and growing home price appreciation due to the inventory shortage, a mix which could end up pushing local buyers out of the market, said Dallas-area loan officer Jennifer Aleman Salazar.

"One of my biggest concerns is affordability. As interest rates are starting to go up, I am rerunning numbers of customers who are qualifying" to determine how much purchasing power they are losing, she said.

Denver is another hot market right now, but that could change if prices rise too much, noted Kelly Moye, a real estate broker who serves as the spokeswoman for the Colorado Association of Realtors.

"A hot market will stay hot for a while until it becomes truly unaffordable for most people," she said.

Here are the 20 cities, listed alphabetically, that are on Amazon's short list, with third-quarter 2017 median sales prices, home sales counts and market size and year-over-year differences provided by Attom Data Solutions — except for Toronto, where the data comes from the Toronto Real Estate Board and is for the full year of 2017.

Data for Boston and Toronto is for the metro area; others are for transactions in the city limits.

Median sales price: $225,000 (-3.8%)
Home sales: 4,842 (-5.9%)
Total single-family homes and condos: 273,192