Big real estate companies are paying top dollar to get their hands on brand new office buildings in Seattle leased to tech titans. The latest example in that trend came earlier this week when New York-based KKR bought the F5 Tower in Seattle and a three-building complex in nearby Bellevue, Wash. that includes a new tower leased to Amazon.

KKR paid $756 million for the Summit complex, a 915,000-square foot, three-building complex that includes a new structure under construction that Amazon leased earlier this year. The deal marks the priciest transaction of the year in the Seattle area and a big return for previous owner Hines, which bought the complex in 2015 for $319 million.

F5 Tower, a striking new office building with prominent placement on the Seattle skyline, sold for $440 million. F5 occupies 28 floors in the building, the entire office portion, with a hotel taking up the rest of the space. F5 started moving employees in earlier this year, and it plans to house more than 1,500 people there.

A jump in state taxes on real estate sales starting Jan. 1 has owners scrambling to unload properties before the end of the year. The Puget Sound Business Journal reported that 19 large assets have sold for more than $3.4 billion in just the last two weeks.