But Wallach points out that during April and May, Pfizer signed an 800,000 square-foot lease at 66 Hudson Boulevard; Latham & Watkins signed a more than 400,000 square-foot lease at 1271 Ave. of the Americas; and J. Crew signed a 325,000 square-foot lease at Brookfield Place, in a deal that made room for Facebook to expand by 295,000 additional square feet at 770 Broadway, (with numbers adjusted according to information provided by the clothing company's broker JLL.)

“Two deals, especially large deals can always determine the outcome of a quarter or a month, if they are large enough to leave a mark,” says Wallach. He further explains that more than half of the total number of leases that close in Manhattan are under 15,000 square feet. “That's the bread and butter of the Manhattan office market in terms of numbers of leases.”

Similarly, with the year-over-year comparison, May 2017 did not have collectively as many large leases compared to May 2018.

The average rent for Manhattan offices increased from $73.36 per square foot in April 2018 to $74.04 in May 2018, and year-over-year it increased from $73.64 from May 2017.

However, Caggiano explains this does not necessarily indicate landlords are raising or lowering rent. In discussing why this needle moves, he says, “It's the law of averages. Prices can rise as large, less expansive space is taken off market. The drag on the asking rent is eliminated and prices can rise because large, less expensive space is taken out of our sample set.”

As to future challenges landlords face, Colliers International has been tracking leases and availability rates and has known for several years that seven million square feet of office space will become available during the upcoming quarters through 2018, and millions more to follow. Colliers' Q1 2018 report warned the market would need to see leasing pick up space or stay at the same level or head towards negative absorption. “This could have a downward effect on pricing,” says Caggiano.

He notes that the denominator of the overall supply of offices added to Manhattan continues to grow. The numerator is shrinking as tenants are taking less space than they would have 10 years ago with greater densification of employees in offices. “Yet with those two factors going on post-Great Recession, we've seen steady leasing activity. We've seen availability stay remarkably stable at around 10%, which many market commentators say is market equilibrium that favors neither tenant nor landlord.”

Noting a historic shift in office leasing that reflects economic trends in Manhattan, Caggiano adds one of the most interesting transactions is Deutsche Bank's plans to move to the Time Warner Center in Q3 2021, when Time Warner relocates to Hudson Yards.

“When Deutsche Bank moves, there will be no major bank with US headquarters on Wall Street,” says Caggiano.

Wallach adds that banks have been leaving Wall Street with the improvement of technology, and with employees commuting from suburbs into Midtown. The industry realized employees did not need to be right by the stock exchange to transact business. He underscores today's trend of more diversified businesses in publishing, media, non-profits, engineering and tech moving downtown—reflecting how New York continues to evolve.