Google, JPMorgan Chase and the new age of spectacularly rich corporate real estate buyers

Now the pendulum is swinging back in the other direction. One reason: the sheer accumulation of wealth in the hands of corporate behemoths. Cash and liquid investments held by U.S. non-financial firms rose by 5 percent in 2017 to $1.9 trillion, according to a November report by ratings agency Moody's. The report projected Google's parent company Alphabet would hold $103 billion in cash by the end of last year. Apple's cash reserves were projected at a staggering $265 billion.

Companies need to store all that wealth somewhere, and low interest rates make bank accounts and bonds somewhat less appealing. Real estate offers an alternative. Meanwhile, the recently passed federal tax reform allows firms to repatriate their offshore wealth at a lower tax rate for a limited time, adding an incentive to move funds from overseas into the New York property market.

Another big change concerns accounting rules. In the past, companies weren't required to list leases as liabilities on their balance sheets, even though that's exactly what they are. But starting in 2019, that will change. Public companies that sign leases will have to include their present value as liabilities, making them look worse on paper. Companies that buy buildings may add liabilities in the form of a mortgage, but they also add a valuable property to their balance sheet.