For office investors, Nashville is the nation's top "buy" market, according to a new report by commercial real estate transaction platform Ten-X Commercial. The other top buy markets are Kansas City, Missouri; Washington, D.C.; and Sacramento and Oakland in California.

The health of an office market now depends on more than just the local economy, Ten-X reports. The once-strong correlation between robust employment and the strength of an office market has disconnected somewhat as employers fit more workers into less space, more employees work remotely and cloud computing reduces the need to for physical space.

The strength of Nashville and the other four top buy markets comes despite trends in the office sector nationwide that are dimming prospects of growing returns. The buy markets tend to have growing populations and employment, but also new and thriving industries that need space.

In Nashville's case, the report said, the office-using professional and business services sector continues to fuel the local economy, with gains in the 5% range. Also, the city tends to be a winner in site selection.

Nashville's effective office rents are still strong, although year-over-year growth has slowed to 3%, the report states citing Reis data. In 2021, office rents are projected to end 2.6% higher than their current rate, and office property net operating income is expected to rise 0.5% annually throughout the forecast period, with gains in 2018 and 2021 bookending 2019 and 2020 declines.

On the opposite end of the spectrum, Ten-X reports Milwaukee topped the list of the five top sell markets in the country.

Milwaukee's weak economic growth is straining the city's office market. Employment growth has been persistently weak since 2016 as the outsized education and healthcare sectors have continued to disappoint. Milwaukee's office vacancy rate came in at 19.7% in Q1, up 50 basis points year over year and marking a cyclical peak. While effective rents rose 1.9% from a year ago, they are expected to decline by 3% by 2021, the report said.

The other sell markets to make the list are suburban Maryland, Chicago, Austin and Baltimore. Booming Austin might come as a surprise on the sell list, but Ten-X predicts that come the next downturn, office supply will overshoot demand in Austin.

One metro area is on both the buy and sell lists, namely metro Washington, D.C. The District itself is a buy, according to Ten-X, thanks to slow-but-steady economic expansion and robust population growth that are pushing office rents upward.

By contrast, suburban Maryland is a sell. The region's important government sector is showing disappointing performance this cycle, with annualized gains ranging mostly between 0% and 2%. The area's office vacancy rate measured 18.2% in Q1, unchanged from a year ago.